The Archaeologist's Manual for Conservation: A Guide to Non-Toxic, Minimal Intervention Artifact Stabilization

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The Archaeologist’s Manual for Conservation

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THE ARCHAEOLOGIST’S MANUAL FOR CONSERVATION A Guide to Non-Toxic, Minimal Intervention Artifact Stablization

Bradley A. Rodgers Program in Maritime Studies East Carolina University Greenville, North Carolina

KLUWER ACADEMIC PUBLISHERS NEW YORK, BOSTON, DORDRECHT, LONDON, MOSCOW

eBook ISBN: Print ISBN:

0-306-48613-X 0-306-48466-8

©2004 Springer Science + Business Media, Inc. Print ©2004 Kluwer Academic/Plenum Publishers New York All rights reserved No part of this eBook may be reproduced or transmitted in any form or by any means, electronic, mechanical, recording, or otherwise, without written consent from the Publisher Created in the United States of America

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To my wife Annie—through thick and thin


Foreword

This is a Foreword by an archaeologist, not a conservator, but as Brad Rodgers says, “Conservation has been steadily pulled from archaeology by the forces of specialization” (p. 3), and he wants to remedy that situation through this manual. He sees this work as a “call to action for the non-professional conservator,” permitting “curators, conservators, and archaeologists to identify artifacts that need professional attention and, allow these professionals to stabilize most artifacts in their own laboratories with minimal intervention, using simple non-toxic procedures” (p. 5). It is the mission of Brad’s manual to “bring conservation back into archaeology” (p. 6). The degree of success of that goal depends on the degree to which archaeologists pay attention to, and put to use, what Brad has to say, because as he says, “The conservationist/archaeologist is responsible to make preparation for an artifact’s care even before it is excavated and after its storage into the foreseeable future” . . . a tremendous responsibility” (p. 10). The manual is a combination of highly technical as well as common sense methods of conserving wood, iron and other metals, ceramics, glass and stone, organics and composits — a far better guide to artifact conservation than was available to me when I first faced that archaeological challenge at colonial Brunswick Town, North Carolina in 1958—a challenge still being faced by archaeologists today. The stage of conservation in 1958 is in dramatic contrast to the procedures Brad describes in this manual—conservation has indeed made great progress. For instance, a common procedure then was to heat the artifacts red hot in a furnace—a method that made me cringe. Faced with the need to treat thousands of wrought nails I was excavating from the ruins of Brunswick Town, I rented a sandblaster and was able to clean the rust from padlocks, hinges, pintles, keys, buckles and tools, as well as wrought nails, at a cost of 25 cents each (South 1962a:18), saying, “No other method can match this achievement.” I also said, “No soaking to remove salts has been found to be necessary,”— a statement that probably makes Brad cringe today. Later I soaked a bucket of nails in a diluted 5% solution of muriatic acid to remove the rust, decreasing dramatically the cost per nail. In 1962, I sent to my supervisor, “Notes on Treatment Methods for the Preservation of Iron and Wooden Objects” (South 1962b), in which I described the treatment of water-soaked wood and iron recommended by various conservators and archaeologists at the time—such as soaking cannonballs in a fresh water stream vii

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FOREWORD

to remove the salts. Artifact conservation was a process being tried using various nefarious, and some efficacious, methods that archaeologists were pulling out of the seat of their pants. In later years my experience with conservators was not the best as that “force of specialization” Brad speaks of widened the gap between professional conservators and the conservation needs I had as an archaeologist. For instance, when a professional conservator was made available to me, I gave 10 nails to the professional to process for use in an exhibit—three months later four were done. I received a promise that the others would be completed within a year—these were not the crown jewels of Europe! Well, back to sandblasting and muriatic acid. Since that time, I have left all Spanish barrels I discover (after recording and photographing them in situ) in the well hole where they have been safely conserved by nature for four and a half centuries. As Brad says: “In-Situ conservation is designed to extend an artifact’s stability in the ground or the sea bottom, a form of preemptive conservation” (p. 10) — a wise method until such a time that conservators can successfully conserve composite artifacts. I could continue, but the point is many archaeologists are very likely still trying to conserve their artifacts by using methods pulled from the seat of the pants, because the sources written by conservators (and there is a definitive listing of them in Brad’s manual) are too complex and technical for use by field archaeologists — yet the responsibility to conserve the artifacts is constantly there. Brad’s manual in this volume is the first attempt to “bring conservation back into archaeology.” It is my hope that this manual will help do that, so further horror stories can be reduced and archaeologists can come closer to achieving “Pinky” Harrington’s goal—“To preserve the physical remains of our past and to employ them in perpetuating our historical heritage” (Harrington 1965:8, quoted in South 1976:42). Stanley South H. H. D. The University of South Carolina South Carolina Institute of Archaeology and Anthropology Columbia, South Carolina

REFERENCES Harrington, J. C. 1965. Archaeology and the Historical Society. The American Association for State and Local History. Nashville. South, Stanley 1962a. A Method of Cleaning Iron Artifacts. Newsletter of the Southeastern Archaeological Conference 9(1): 17–18. —. 1962b. Notes on Treatment Methods for the Preservation of Iron and Wooden Objects (Unpublished manuscript, North Carolina Department of Archives and History, Brunswick Town State Historic Site, Raleigh. —. 1976b [1972]. The Role of the Archaeologist in the Conservation-Preservation Process. Pp. 35– 43. In Preservation and Conservation Principles and Practices. Edited by Sharon Timmons. Produced by the Smithsonian Institution Press. Published by the National Trust for Historic Preservation in the United States. The Preservation Press. Washington, D.C.

Preface

This project began over a decade ago in my first attempt to produce a manual that outlined the procedures used at the artifact conservation laboratory at East Carolina University to stabilize and conserve water-degraded archaeological artifacts. The Conservator’s Cookbook (1992), became a practical conservation manual designed to compliment graduate level conservation classes. The text and flow charts provided simple hands-on advice to students who wanted to conserve artifacts. Complimenting the conservation manual was the Conservation of Water Soaked Materials Bibliography (1992), by far the most comprehensive listing of books and articles yet compiled concerning archaeological artifact degradation, conservation, and stabilization. These texts enjoyed surprising popularity, inspired no doubt by the fact that they endorsed practical application and methodology in the midst of a field whose literature was dominated by theory with anecdotes from spectacularly difficult ostentatious projects. At that time, however, crossover students from the Department of Anthropology began to add great scope to my experience, expanding significantly the types and conditions of artifacts brought into the laboratory for conservation. I soon discovered that although the treatments in the Conservator’s Cookbook were specifically designed to stabilize water soaked and degraded artifacts, they worked equally well or better on artifacts recovered from land sites. Indeed, the procedures devised for water-degraded material, reflected a considerable advance over those employed to stabilize artifacts in most terrestrial laboratories. Experience proved that the famed preservation properties of seawater are simply an anomaly of available conservation technology. In other words, given the same treatments, artifacts excavated from the ground demonstrate equal or better preservation to those recovered from wet sites. It also became clear that dry recovered artifacts can be conserved in a condition that permits detailed microexcavation and examination of both prehistoric and historic objects. Native American copper ornaments from Fort Neoheroka (1713) could be examined for signs of use and polishing. What was thought to be a concreted gun barrel from Santa Elena (1572) was found to be no more than a mandrel rolled piece of sheet iron, and buttons and coins lost all concretion and accumulated filth to reveal dates, maker’s stamps, gilding, mold marks, and wear that was never seen before. In light of these discoveries it became increasingly clear, that despite the fact that underwater archaeology is a much younger field than prehistoric and ix

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PREFACE

historic archaeology and owes much to its parent fields, it is now well ahead in artifact conservation technique and practice. The Archaeologist’s Manual for Conservation is the first attempt to share these hard won conservation advances with the archaeological field as a whole, and demonstrate for the first time that hands-on conservation should be endemic to the entire profession; prehistoric, historic, and underwater.

Acknowledgements

Every author is in debt to innumerable people who share ideas, concepts, and opinions, but most of all, to those who offer encouragement. Without a first step, a book remains only a pipe dream, and few first steps are taken without encouragement. In this light I would like to thank my colleague Dr. Annalies Corbin, for her ideas, help in proofing, and sage advice to the effect of, “what are you waiting for”? She and Dr. Nathan Richards shouldered heavy burdens as I worked, proof positive that “old fashioned teamwork” is, without question, still alive and well. Dr. Richards also provided fine detailed line drawings that elucidate conservation concepts far beyond the means of written text. I would also like to thank my graduate help, Mr. Dave Krop, Mr. Andrew Weir, Ms. Claire Dappert, and especially Ms. Dannielle La Fleur, your diligence and hard work are much appreciated. Special thanks go to Mr. Christopher F. Valvano for the photographs, each a major endeavor. Scientists can sometimes focus their entire attention on concept detail— learning a lot, about a little. Conservation science is the opposite. An archaeologist/ conservator needs to know a little, about a lot. It is good to have friends, therefore, who can give sound and specialized advice. In this light I would like to thank Mrs. Marcia Kuehl, chemistry consultant and old friend and Dr. Charles Ewen for making available the collections at the Phelps Anthropology Laboratory for study and preservation. Final thanks go to my wife Ann for your encouragement and patience. Rusted log staples don’t belong on the kitchen table and I won’t tell you what has been in the freezer.

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Contents

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xv

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1

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7

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33

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69

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105

5. Miscellaneous Archaeological Metals: Au, Ag, Pb, Pewter, Sn, Al . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

123

List of Figures

Introduction: Conservation Is Part of Archaeology 1. The Minimal Intervention Laboratory 2. Archaeological Wood

3. Archaeological Iron (Fe)

4. Archaeological Copper (Cu) and Copper Alloys

6. Archaeological Ceramic, Glass, and Stone

. . . . . . . . . . . . . . . . . . . . 139

7. Organics Other than Wood

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159

8. Archaeological Composites

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185

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201

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205

Appendix: List of Journals Index

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List of Figures

Chapter 1 A Minimal Intervention Artifact Conservation Laboratory. . . . . . . . The A,B,Cs of Minimal Intervention Lab Design Philosophy. . . . . The Bulking Agent Recovery Tank (BART) system at the artifact laboratory, Program in Maritime Studies, East Carolina University.

10 11 19

Chapter 2 Archaeological Wood Treatment Flow Chart. . . . . . . . . . . . . . . . . Compendium of Treatments for Archaeological Wood. . . . . . . . . . Wood mainly comprised of the complex carbohydrate cellulose. . . The three directions of collapse and shrinkage in Archaeological Wood. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

33 34 37 38

Chapter 3 Archaeological Iron Treatment Flow Chart. . . . . . . . . . . . . . . . . . . Compendium of Treatments for Archaeological Iron. . . . . . . . . . . . An 18th century cast iron pipkin from a fresh water site. . . . . . . . . Wrought iron log staple of the 19th century. . . . . . . . . . . . . . . . . . Brass buckles with iron pins. . . . . . . . . . . . . . . . . . . . . . . . . . . . . Typical brown mass concretion of terrestrially recovered iron nail. . Wrought iron log staple undergoing dry cycle decomposition. . . . . Sulfate reduction and Methanogenesis in an anaerobically interred iron nail. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Hollow concretion from an ocean site. . . . . . . . . . . . . . . . . . . . . . Pourbaix diagrams. Two different configurations. . . . . . . . . . . . . . Weeping corrosion breaking out on 17th century cast iron cannon. . Nearly perfect preservation exhibited by a 19th century flat iron recovered from a fresh water site. . . . . . . . . . . . . . . . . . . . . . . . Set up for electrolytic reduction. . . . . . . . . . . . . . . . . . . . . . . . . . . Graph of chloride rinsing in a large iron artifact in parts per million of chloride ion concentration vs. time in weeks squared. . . . . . .

xv

69 70 72 73 76 77 79 80 81 82 84 86 89 93

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LIST OF FIGURES

Chapter 4 Archaeological Copper and Copper Alloys Treatment Flow Chart. . Compendium of Treatments for Archaeological Copper and Alloys. Copper alloy rivet undergoing differential aeration corrosion or “necking”. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Copper alloy undergoing Pitting corrosion. . . . . . . . . . . . . . . . . . . Dezincified brass bolt. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Copper alloy concretion beginning with the deposit of calcium carbonate on an alkaline surface just above the corrosion product. Turn of the 20th century fishing boat brass carburetor with generalized corrosion and salt intrusion between the flanges. . . . Early 18th century brass bells with iron clappers from Fort Neoheroka. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

105 106 110 111 111 112 116 117

Chapter 5 Miscellaneous Archaeological Metals Treatment Flow Chart. . . . . Compendium of Treatments for Miscellaneous Archaeological Metals and Alloys. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Silver Plated Cigarette Lighter manufactured by R. Wallace and Sons Co. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Lead gaming piece part way into its galvanic wrap conservation. . .

123 124 126 127

Chapter 6 Ceramic, Glass, and Stone Treatment Flow Chart. . . . . . . . . . . . . . Compendium of Treatments for Ceramic, Glass, and Stone. . . . . . . Hard paste porcelain, salt glaze stoneware, and pearl white earthenware. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Devitrifying glass bottle bottom. . . . . . . . . . . . . . . . . . . . . . . . . . .

139 140 145 147

Chapter 7 Organic Archaeological Artifacts Other Than Wood Treatment Flow Chart. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Compendium of Organic Archaeological Artifact Treatments. . . . . Textile and cordage cleaning table that can be flooded with water to a depth of one inch. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Treated braided rope from an early 19th century site. . . . . . . . . . . . Early 19th century leather shoe before conditioner application. . . . Bone handled knife treated in separate pieces. . . . . . . . . . . . . . . . .

159 160 166 170 172 173

LIST OF FIGURES

xvii

Chapter 8 Archaeological Composites Treatment Flow Chart. . . . . . . . . . . . . Some examples of composite metal artifacts—nickel plated iron drawer pulls and brass and iron buckles, along with a solid lead gaming piece. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Wood and iron composite pulley block sheave. . . . . . . . . . . . . . . . A bone handled fork treated as a composite artifact. . . . . . . . . . . .

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189 192 195


Introduction Conservation Is Part of Archaeology

This manual is designed to take the mysticism out of archaeological artifact conservation and act as both reference and guide. It is intended to be a tool to assist archaeologists in stabilizing a majority of the artifacts they excavate, or those already in storage. These stabilized archaeological collections will be preserved into the future, permitting reexamination and multiple interpretations of the data as our knowledge base grows through time. In addition, conservation will permit improved in-depth primary artifact interpretation, as fully conserved artifacts reveal fabrication, wear patterns, and detail impossible to detect in non-conserved artifacts. Conservation, therefore, is a critical tool within archaeology, a tool that becomes less meaningful if it is isolated, or seen as merely a technical skill that can be farmed out to the “hard sciences.” The Archaeologist’s Manual for Conservation is intended as a counterpoint to the popular specialization trend. My goal in offering this manual is to put artifacts back in the hands of archaeologists or material culture specialists who can best decipher them, opening avenues of artifact or material culture interpretation that are disappearing as artifacts either decay in storage or are sent away to the “conservation professionals.” Yet it cannot be denied that artifact conservation has become an increasingly complex subject. The manual, therefore, is divided into chapters of material types and subdivided into easily understood components within each chapter, each backed by extensive bibliographic reference. Of the hundreds of treatment concepts available today, the few promoted in the manual are chosen for their effectiveness, simplicity, lack of toxic effects (on both conservator and environment), and cost effectiveness. All treatments must also conform to the rules of conservation specified in Chapter 1. The Archaeologist’s Manual for Conservation can be approached on several levels. It can be read in narrative form for those interested in a particular material or conservation procedure, or used as a practical reference by following the artifact treatment flow charts on the first page of each chapter. Chapters open with material theory and take the reader through first, a short history of a material followed by a theoretical description, including the refining process if the material is a mineral, or the biology of the substance if it is an organic. Theory sections will also describe the decomposition and deterioration of an artifact. The practical side of the manual 1

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INTRODUCTION

follows the theoretical sections. Methodology explains in detail how any given material type is stabilized.

HOW THE MANUAL WORKS AND ITS ANTECEDENTS The Archaeologist’s Manual for Conservation outlines practical methodology in simple flow chart form. The flow charts demonstrate how an artifact can be stabilized from start to finish and the reasoning behind the use of the method deemed most effective. The flow charts are located on the first page of each chapter concerning a particular substance such as wood, iron, copper, glass, ceramic, and so on. Treatment simply follows the logic of the flow charts. Since the actual explanation for flow chart procedures is fairly complex, and much too detailed to fit the confines of the diagram, each procedure in the chart refers to the pages in the text where that treatment is explained. The methodological explanations also reflect insights on similar or related materials or procedures. Identifying the substance that makes up an artifact is equivalent to finding the ON switch to this manual. It allows a technician to turn directly to the flow chart guiding treatment for that material. Though material make-up is obvious in most instances, a technician’s ability to identify the elements that make up an object may at times be difficult. Strategically this task is of paramount importance, as it forms the basis for all subsequent treatment. At times it is not good enough to simply identify that an artifact is made out of wood, ceramic, or iron. Treatment often depends on the particular type of wood, ceramic, or iron. Archaeologists and curators trained in material culture and conservation procedures, enjoy a distinct advantage in this area over nonarchaeological conservators. Their experience permits them to determine artifact and material type at a glance, despite its present condition or accumulated concretion. A scupper liner for example will always be lead, a nail will always be wrought iron, and a cannon ball will almost always be cast iron. Conservators not trained in archaeology or artifact identification are often forced to rely on material analysis alone to confirm material type, adding time and cost to the conservation procedure. Artifact typing argues powerfully for a continuous dialogue between conservators, curators, and archaeologists if not cross training in these professions. The Archaeologist’s Manual addresses material typology with simple diagnostic methods and a list of traditional artifacts fabricated of that material at the beginning of each chapter. These identification methods are usually effective in separating materials precluding the use of more sophisticated and costly methods of identification such as X-ray diffraction analysis, PIXI, and gas chromatography. However, these procedures do have their uses and can be found in most physics departments in local universities. Textile and organic analysis can also be accomplished in a Home Economics or Biology Department. Networking is

CONSERVATION IS PART OF ARCHAEOLOGY

3

encouraged in conservation and is often the key to promoting good and complete analysis of an artifact. This manual will also list most of the other conservation methods currently available for treatment of a certain sort of material in chart form following the treatment flow chart. The treatments compilation chart will not go into detail concerning how these other methods are used, only that under certain circumstances, they are, or have been in the past. This simple list of conservation methods is augmented by a chapter by chapter bibliography of up to date research in the various journals and publications concerning conservation of artifacts. Therefore, each section of material type is serviced with a listing of the latest sources. If an article or book covers more than one type of material it is included in the bibliographies of each of the material types mentioned. General conservation works are included after Chapter 1, “The Minimal Intervention Laboratory.” Research for this manual includes over 1000 books and articles gleaned from over 100 journals in conservation, archaeology and related fields in engineering, biology, wood science, chemistry, biochemistry, as well as various curatorial journals (see appendix A). Conservation is a relatively new field within archaeology and few books specifically address archaeological conservation. Most of the classic references in conservation are written from the point of view of a museum curator. These include Plenderlith and Werner’s, The Conservation of Antiquities and Works of Art, first published in 1956, and Muhlethaler and Barkman’s Conservation of Waterlogged Wood and Wet Leather, 1973. More recent books concerning archaeological conservation include, Colin Pearson, ed., Conservation of Marine Archaeological Objects, 1987; J. M. Cronyn’s, The Elements of Archaeological Conservation, 1990; Donny Hamilton’s, Basic Methods of Conserving Underwater Archaeological Material Culture, 1996, as well as specialized works such as Wayne C. Smith’s, Archaeological Conservation Using Polymers, 2003. Though excellent sources of information in their own right, they tend to be written from a theoretical perspective and are generally speaking, written for conservators, conservation scientists, or archaeologists with substantial backgrounds in artifact stabilization theory. In essence, they do not completely cross the practical application gap, and in fact, tend to create an artificial separation between conservation and archaeology. At times, however, practical research has surfaced. Works by Wendy Robinson, First Aid for Marine Finds, 1981, followed by Catherine Sease’s, A Conservation Manual for the Field Archaeologist, 1987, and Katherine Singley’s, The Conservation of Archaeological Artifacts From Freshwater Environments, 1988, attempted to bring conservation back within the realm of practical application and archaeology and succeeded in doing so to some degree. Unfortunately, a more comprehensive fully practical manual did not immediately follow their lead and conservation has been steadily pulled from archaeology by the forces of specialization.

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INTRODUCTION

CONSERVATION AND ARCHAEOLOGY Colin Pearson states in the Preface of Butterworth’s, Conservation of Marine Archaeological Objects that, “excavation without conservation is vandalism (Pearson, 1987: Preface)”. It should be stated plainly here that this is true not only for artifacts recovered from underwater sites, but artifacts recovered from terrestrial excavations as well. Yet, one of the great myths in terrestrial archaeology is that artifacts are safe and stable simply if they are cleaned of surface debris, tagged, and stored. In reality, the deterioration process and chemical breakdown of artifacts recovered from a marine environment, a freshwater or wet site environment, or a terrestrial environment, will continue even after drying and storage. This is particularly true of metals and organics. The difference seems to be the rate at which artifacts disintegrate. Generally terrestrial and fresh water or wet site recovered artifacts deteriorate at a somewhat slower pace than artifacts recovered from the sea, even though objects recovered from the ocean may initially look like they are in better shape. But deterioration is inevitable in both land and water recovered artifacts. Material recovered from any of these physically different sites cannot always be effectively stabilized with simple exterior cleaning and storage and short term observations (several years) are not always a reliable indicator of whether an artifact is stable. Curation has no time limit, artifacts are expected to last as long, for all practical purposes, as our civilization does. Therefore, conservation is a necessity for longterm artifact storage, without it an object’s life span is greatly reduced. The reasons for artifact deterioration are complex and vary with each artifact, but stated simply, in most instances an archaeological artifact has reached a natural chemical and electrical equilibrium with its environment, whether with the ground or the ocean benthic environment. When that equilibrium is disturbed through excavation, the artifact will begin to break down. Since artifacts recovered from the ocean break down at a spectacular rate, underwater archaeologists have been forced to devise techniques to counteract artifact deterioration. The old standard practice of most archaeological laboratories, exterior cleaning and storage, had no appreciable affect in stabilizing water-degraded artifacts. The tagged, bagged, boxed, and shelved practice is an alarming yet unquestioned modus operandi for most archaeological laboratories; alarming because the artifacts so processed are NOT necessarily stable and may deteriorate over time even in air tight containers. Years after the artifacts are put away for ”safe keeping,” when the contents of the storage containers are examined (or rediscovered as it were), one of three observations will invariably take place. First, if the artifact is robust (lithic, bone, glass, or ceramic) it may appear that it is normal, or perhaps it is a slightly different hue, color, or iridescence than its accession photograph. The curator is left to decide if the photo or the artifact is changing color, but no great injury or harm seems to have been done to the artifact. Second, a more friable sort of artifact (metallic, textile, cordage, organic, or wood) has over time become several artifacts while untouched in its storage box. This artifact is actively spalling,

CONSERVATION IS PART OF ARCHAEOLOGY

5

breaking up, and or leaving residue. In most laboratories this is overlooked, seen as normal aging, or perhaps the result of a storage problem. In the third scenario the curator opens the artifact storage box and is left to guess where the artifact went, and who replaced it with a pile of dust and debris? These scenarios are obviously a temporal snapshot of what will happen to many artifacts in storage (even some of the more robust specimens) that have not undergone conservation, and these scenarios are repeated at virtually every archaeological laboratory in the country. The Archaeologist’s Manual for Conservation is intended to allow archaeologists and curators of archaeological artifacts to examine their collections in a whole new light, permitting these professionals to view the effects of time on unstabilized artifacts for what it really is, a destructive process with only one eventual outcome. This manual can be seen as a call to action for the non-professional conservator. It will permit curators, conservators, and archaeologists to identify artifacts that need professional attention and, allow these professionals to stabilize most artifacts in their own laboratories with minimal intervention, using simple non-toxic procedures. In this way The Archaeologist’s Manual is somewhat iconoclastic and works to dispel the notion that all archaeological conservation is too difficult and complex for the average curator or archaeologist. It will remove or explain in simple terms professional conservation language. For although professional language promotes easy communication within a vocation, it intimidates and distances people outside a profession. For so long as curators and archaeologists buy into the notion that conservation is too complex and difficult a subject to tackle on their own (on any level), the collections will continue to languish under inaction and neglect. The final irony remains that while many objects could be saved with very simple procedures, they may in fact be doomed while awaiting professional attention, professional attention that may simply be too costly to be practical. Few archaeology labs can hire professional conservators, and fewer still can afford to ship their entire collections to those laboratories that can stabilize them. Though The Archaeologist’s Manual for Conservation suggests that curators and archaeologist can take care of some of their conservation needs, it does not intend to imply that neophyte conservators attempt to stabilize large complex or complicated composite artifacts. Overly complex projects concerning valuable artifacts or works of art should be left to teams of professional conservators working with the latest scientific equipment and knowledge of the subject. A general rule of thumb for this manual is, if a reader has concerns about an artifact, or is unsure of their ability to stabilize an object without damage; it should go to a professional or a professional should be consulted. Conservation can be a very complex subject and is governed by how highly degraded an object may be, the type of degradation it has suffered, the rules of conservation, goals of treatment, laboratory philosophy, and laboratory type. The size and scope of this manual is manageable only by assuming that the reader here is concerned with the least complex of conservation goals (stabilization), the simplest laboratory type, and the least intrusive non-toxic, safe procedures. Complex and specialized procedures are included within written

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INTRODUCTION

research in the chapter bibliographies, but are not considered relevant to the scope or design of this book. In the final analysis The Archaeologist’s Manual for Conservation is an attempt to make archaeologists and archaeological curators aware that artifacts are not just a valuable resource recovered during an excavation, but can continue to shed light on a site long after excavation and recovery. But only if the recovered objects are preserved into the foreseeable future. In practical application, conservation techniques and micro-excavation analysis can add a great deal to the interpretation of any site. Conserved artifacts more easily reveal adaptively reutilized artifacts, tool patterning, manufacturing techniques, wear patterns, stains, gilding, makers marks, mold marks, nicks and dents from use. However, this manual is simply a tool. The archaeologist/ conservation technician must make it work and bring conservation back into archaeology.

INTRODUCTION: CONSERVATION ETHICS SOURCES Anon. “A Code of Ethics for Conservators.” Museum News 58:4 (1980): 28–34. [ECU-109] Appelbaum, B., and P. Himmelstein. “Planning for a Conservation Survey.” Museum News 64:3 (1986): 12–14. [ECU-226] Arnell, Jack. “The Importance of Conservation Must be Recognized.” Bermuda Maritime Museum Quarterly II (1989): 22. [ECU-12] Ashley-Smith, J. “The Ethics of Conservation.” The Conservator 6 (1982): 1–5. [ECU-412] Croome, A. “Boost for Marine Archaeology.” New Scientist 50:257 (1971): 746–747. [ECU-112] Hamilton, Donny L. “Conservation in Nautical Archaeology.” Proceedings (12th Conference on Underwater Archaeology, 1981). [ECU-39] Leigh, D. “Reasons for the Preservation and Methods of Conservation.” Marine Archaeology. D.J. Blackman, ed., Anchor Books, 1973: 203–218. Lodewijks, I.J. “Ethics and Aesthetics in Relation to the Conservation and Restoration of Waterlogged Wooden Shipwrecks.” Conservation of Waterlogged Wood (1979): 107–110. [ECU-313] Logan, Judith A. “Thoughts on the Role of the Archaeological Conservator.” CCI Newsletter (Canadian Conservation Institute) (1988): 810. [ECU-51] Organ, R.M. “A Conservation Institute: A Personal Concept.” Journal of the American Institute for Conservation 2 (1975): 63–65. Pearson, C. “Legislation for the Protection of Shipwrecks in Western Australia.” ICOM Proceedings (1975). Peterson, Curtiss E. “The Role of Conservation in the Recovery of the USS Monitor.” Proceedings (15th Conference on Underwater Archaeology) (1984): 195–196. [ECU-75] Rodgers, Bradley A. “Introduction.” The East Carolina Conservator’s Cookbook: A Methodological Approach to the Conservation of Water Soaked Artifacts. Herbert R. Paschal Memorial Fund Publication, East Carolina University, Program in Maritime History and Underwater Research, 1992. [ECU-402] Tighe, Mary Anne. “The Right Restorer.” Washingtonian (February 1972): 121–122. [ECU-393] Ullberg, A.D. and R.C. Lind, Jr. “Consider the Liability of Failing to Conserve Collections.” Museum News (1989): 32–33. [ECU-1131

Chapter 1 The Minimal Intervention Laboratory

ARCHAEOLOGICAL CONSERVATION Artifact conservation has been defined in several different ways depending on the professional viewpoint of the author. Archaeological artifact conservation for instance, can be defined in a somewhat more restrictive manner than art or building conservation, that usually includes phrasing concerned with restoration. Unlike historic site curators or professional resource managers, archaeologists are not generally concerned with restoring an artifact to anything approaching its original appearance, and in fact, can tell more about an object if it is worn, well used, and broken, than if it is in pristine condition. While archaeological conservation places no premium on restoring an artifact’s appearance, it does become a more inclusive profession in other respects. Lindstrom and Rees-Jones define marine archaeological conservation in two ways stating that the goals of conservation are “the control of the environment to minimize decay” and secondly, “to stabilize them [artifacts] where possible against further deterioration (Pearson, 1987; Series Editor’s preface).” The multi-component approach to archaeological conservation is a point well taken and over the years it has become more encompassing. Since this definition was postulated, the separation between archaeologist, and archaeological conservator and, curator has become, if anything, more blurred. Job distinctions now depend on where the skills of a crewmember fit into the overall archaeological team and how the team is set up in the planning for fieldwork. Archaeological conservators and conservation technicians don’t just work in laboratories anymore than archaeologists only work in the field. It becomes even more convenient if they are one and the same person. Nonetheless, the new conservator/ archaeologist actually begins the conservation process during the initial project research design, when it is planned that artifacts will, or perhaps will not (as in the case of a pre-disturbance survey), be recovered. Current interest in cultural resource management (CRM) emphasizes that artifacts be removed from a site only under the best planned circumstances, and only if certain conditions are met. Namely that conservation funding be set in place before the excavation, or a fully capable laboratory and staff support the field work while museum, state, or academic facilities agree to store and curate the artifacts. As archaeological conservation becomes more widespread and implemented, 7

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artifacts can even receive in-situ stabilization treatment and be left in place. In-Situ conservation is designed to extend an artifact’s stability in the ground or the sea bottom, a form of preemptive conservation. Therefore, in a modern sense, archaeological artifact conservation starts well before any artifact is excavated and continues well after an artifact is curated. The definition of conservation has to be inclusive and the conservator by necessity wears many hats. For the purposes of this text archaeological artifact conservation is; the designed implementation of processes, procedures, and strategies to guard artifacts and archaeologically important objects, as far as possible, against deterioration on site, during recovery, while transitioning to storage, or while in storage or under curation and or exhibit. Conservation in this sense is a verb that also includes the micro-excavation and examination of artifacts as they undergo treatment, in an effort to gain information concerning artifact fabrication, site formation process, use, and wear. This definition is far reaching and temporally has no boundaries. The conservator/archaeologist is responsible to make preparation for an artifact’s care even before it is excavated and after its storage into the foreseeable future. It is no coincidence that as more archaeologists are trained in both conservation and cultural resource management—that fewer and fewer artifacts are being recovered from archaeological sites, they represent a tremendous responsibility. After all, the object of archaeology is the collection of data and information to add to our knowledge base of the human past, full excavation with recovery of every artifact at a site may be unnecessary and comes with a large price, curation and conservation, in the end, are forever.

COMPREHENSIVE LABORATORIES Conservation facilities supporting archaeological work range in size and complexity. There is no general principle concerning laboratory size only general principles regarding design for intended use. For the sake of organization most artifact conservation facilities can be divided into three categories, large comprehensive purpose built facilities, mid-sized complete service facilities (that have generally grown through contract work from program oriented labs), and program supporting laboratories (the special concern of this manual). Laboratory size, in square footage, is not necessarily an indicator of how well a laboratory can perform, nor is budget or equipment. Since archaeological conservation is extremely labor intensive, a far better indicator of lab performance is the knowledge, expertise, and experience of the conservator and technicians working at a lab. There are few large purpose built archaeological conservation laboratories in the world. Comprehensive laboratories operate on large budgets, are university, government, community, contract and grant supported. They may employ scores of conservation scientists and technicians and originally were constructed from the need to support large, state, university, or national projects. Examples of comprehensive conservation facilities include the Canadian Conservation Institute, the

THE MINIMAL INTERVENTION LABORATORY

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Maryland Materials Laboratory, the Texas A & M Laboratory, the CSS Hunley Laboratory, the Mary Rose Laboratory, the Vasa Laboratory in Stockholm, the Skuldelev Laboratory in Denmark, and the Western Australia Maritime Museum Conservation Laboratory. Over the years Comprehensive labs have produced and pioneered the techniques that have laid the foundation for advances in the field of marine archaeological conservation. However, since the majority of these laboratories were built to conserve artifacts from shipwreck sites there has been a disconnection in the transfer of advanced conservation technology to terrestrial archaeology laboratories. The reasons for this divide are understandable. The techniques used and pioneered in the large comprehensive facilities were intended for water-degraded materials. The technical relevance of using marine techniques for dry land excavated materials was a largely unexplored question, answered through the experience of smaller duel purpose facilities. Mid-sized, complete service laboratories picked up these techniques and began to use them for both land and sea recovered artifacts. The duel use of these conservation techniques has since proved that the techniques originally intended to stabilize water degraded artifacts work extremely well on objects recovered on terrestrial sites.

COMPLETE SERVICE LABORATORIES Mid-size Complete Service Laboratories bridge the gap between the large comprehensive labs and simple program supporting archaeology laboratories known for our purposes as Minimal Intervention Laboratories. Mid-sized complete service labs pass on this knowledge first by researching different conservation methods for their own use and then using and passing on the most efficient, cost effective conservation techniques developed by the large Comprehensive Labs. Generally speaking, Complete Service Labs have evolved from small program supporting university labs by using contracts and grants to acquire and build some of the specialized equipment needed. Complete service facilities are often called on to handle virtually any conservation problem from terrestrial or underwater sites yet their budgets and facilities are not up to the standards of the large comprehensive facilities. Complete service laboratories must rely on only the most cost effective dependable conservation techniques, since they cannot afford the expense of redundant procedures, equipment, and chemical storage. By-and-large the use of toxic chemicals and questionably dangerous procedures has also been eliminated at these laboratories for the safety of the student technicians working there, and to cut costs in dealing with expensive, perhaps redundant, equipment and difficult to handle and dispose of chemicals. Full service labs spend a good deal of time in researching conservation procedures that fit within the parameters of the laboratory design, philosophy, and budget. A mid-size complete service lab, as its name implies, can conserve virtually any artifact, but cannot offer the variety of conservation techniques presented by the comprehensive facilities.

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Figure 1.


Figure 2.

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MINIMAL INTERVENTION LABORATORY (MIL) MISSION MILs include most academic anthropological laboratories, non-profit archaeological support laboratories, and laboratories set up to support contract archaeology. These aren’t necessarily small laboratories in size, but most of their space is devoted to storage of recovered artifacts and very little space is actually designated for actively treating and stabilizing artifacts. A MIL can contain acres of boxes and shelves yet may not have so much as a fume hood or vapor proof ventilation fan to facilitate electrolytic reduction of metals. Cleaned, tagged, bagged, and boxed, is the traditional conservation method for artifacts curated in these labs, a method that needs update and revision if the collections are to stand the test of time. The methodology outlined in the following chapters for carrying out laboratory objectives are based on a set of ethical and practical codes derived from published conservation sources and accumulated practical experience. The following profile of these principles is set in order of importance and should help shape the objectives of a minimal intervention laboratory (Figure 1, page 10). 1. Health should never be compromised for conservation. 2. All treatments should be reversible (Pearson, 1987; ed. Preface). 3. Use the simplest procedures with the least intervention (Pearson, 1987: 123). Ramp up treatment procedures as necessary. 4. Use multipurpose equipment and chemicals. 5. Do not delay treatment. 6. Work to the ability of the conservator and the resources of the laboratory. 7. All work should be documented (Pearson, 1987; ed. Preface). 8. Normal artifact ageing should not be disguised or removed (Pearson, 1987; ed. Preface).

1. Health Should Never Be Compromised for Conservation If two or more treatment procedures are shown to be equivalent, or nearly so, the procedure demonstrably less harmful on a personal and environmental level will be chosen in every case. No object or artifact is worth compromising the health or well being of an individual or community. Most treatments and tests today can be conducted in a safe non-polluting manner with the artifact left in a safe condition to handle on completion of treatment. Reasons for this corollary are easily seen. The minimal intervention laboratory is based on simple procedures and equipment and is not staffed or equipped to deal with storage and use of major amounts of toxic or dangerous substances particularly heavy metal salts used in chemical testing and organic solvents used to dissolve bulking or impregnating agents. Nor is the minimal intervention laboratory ethically able to support expensive and specialized equipment when simple inexpensive equipment has proven, in most cases, to be as effective.


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Obviously this corollary is a matter of professional philosophy, and there are times even in the minimal intervention laboratory when flammable solvents and dehydrating agents are used. In these instances the dangers will be explained, and the proper precautionary measures spelled out.

2. All Treatments Should Be Reversible This is a universally accepted notion in artifact conservation. Viewed in the context of generations, any conservation treatment used today has to be viewed as a temporary measure. Advances in conservation science will dictate new and better treatments in the future and present day approaches will become obsolete. It makes sense, therefore, since any treatment attempted today may have to be reversed, that this eventuality be planned for in advance. It can be argued that on a molecular level that no treatment is fully reversible. This of course may be true, it is virtually impossible to rinse every molecule of a bulking or impregnating substance from wood cell walls, particularly if the chemical has bonded to the wood fibrils and it may also be impossible to remove every molecule of a coating from a metallic artifact. Yet, reversibility, as a principle, should be adhered to. The argument against reversibility on grounds that all chemicals cannot all be rinsed is specious. If it is necessary to remove a reversible substance, the few remaining molecules will not interfere with the introduction of new treatment substances. And non-reversible procedures, even those that show promise in the short run, cannot be tested beyond our mortal frame of reference in viewing and caring for artifacts. The artifacts, in the end, must be able to survive longer than conservation agents placed in, or on, them.

3. Use the Simplest Procedures with the Least Intervention The object of artifact conservation treatment is to preserve the appearance, internal microscopic integrity, and dimensions of an artifact as far as possible. Often, at least at a large comprehensive conservation laboratory, there are several conservation methods available per material type. This is not the case at a minimal intervention lab. A minimal intervention lab will use the easiest, non-toxic procedures and techniques to insure that the laboratory will be cost effective. Minimal intervention labs will not have redundant equipment, multiple chemicals that have similar uses, or technicians trained in complicated, toxic, or costly and superfluous procedures. This will save money, time, effort, and laboratory space. It will also save intangibly by eliminating storage space for chemicals and used toxic chemicals. But even simpler laboratories can ramp up their treatments to satisfy the needs of individual artifacts, either by adding more treatment time, or gradually increasing the strength of solvents and stain removers.

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Minimal intervention implies that an artifact will undergo the least cleaning, handling, and treatment needed for its complete stabilization. This will save time and artifact handling per unit making the lab more efficient in artifacts preserved per conservation man/hour. Efficiency can be important in a lab suddenly inundated with artifacts, as is periodically the case. The simplest procedures do not, by any stretch of the imagination, suggest that the artifact conservation has been compromised. To the contrary, the basis of this manual is the concept that all treatments have been studied according to stabilizing performance, cost, need for equipment, and simplicity. The best treatments, given the parameters of a minimal intervention non-toxic lab, are presented in this manual.

4. Use Multipurpose Equipment and Chemicals The minimal intervention lab should be set up as efficiently as possible. Laboratory organization suggested in this manual takes into account the varied procedures for different materials and invariably promotes the technique that is most adaptable to different materials. For example, multiple electrolytes (acids and bases) have been suggested in conservation literature depending on type of metal to undergo treatment. Yet arguably, non-toxic sodium carbonate acts equally well for all metallic electrolysis. Sodium carbonate can also be used for metallic artifact pre-treatment, and combined with sodium bicarbonate acts as a rinse and post treatment for several metals. It is an easy choice for electrolyte at the minimal intervention laboratory, saving space, clutter, and complexity. Polyethylene glycol (PEG) and sucrose are proven non-toxic bulking agents. They do not wear out by the time a treatment is finished and in fact, it has been observed that they remain viable for years after their first use. An efficient laboratory will simply evaporate the water from the treatment solution and use both the PEG and sucrose over again and again. This efficiency will lead to greater laboratory cost savings, simpler techniques, and less clutter for additional work place safety.

5. Do Not Delay Treatment Conservation laboratories cannot always keep up with the volume of material excavated. This is particularly true when conservation planning has not been thoroughly calculated into the research design of a project. Backlogs of material and delayed treatment times become the unfortunate outcome of such planning. Treatments may also be delayed because some individual artifacts pose incredibly difficult conservation dilemmas and are placed on the “back burner” while less difficult to treat artifacts are finished. As mentioned, most artifacts reach an electro-chemical equilibrium with their environment over time. Excavation and or removal of an artifact from this balanced environment upsets this equilibrium and usually begins the decay process


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at an accelerated pace. Artifacts often survive for centuries on site better than a few months or years in storage awaiting treatment. It is the conservator’s duty to process artifacts in a timely manner. If treatment delay is a reoccurring problem, overall project research design and site excavation methodology should be reevaluated.

6. Work to the Ability of the Conservator and the Resources of the Laboratory This ethical code is a real test of personality. Some conservation technicians will take on projects that are well beyond their experience and expertise, while others will call for help immediately when the unexpected happens. Minimal intervention lab technicians need to work between these extremes. Working beyond experience level can lead to disaster, and cannot be recommended for valuable, important, or non-robust artifacts. On the other hand, valuable experience can be acquired through technical lab practice in preserving multiple redundant artifacts (example: a keg of nails). Chances are, even practice or classroom training stabilization is more attention than most artifacts will ever receive. All laboratories, however, have their limits. A laboratory fitted with the finest equipment is only as good as its conservator and no conservator has done and seen everything. The best conservator’s know when an artifact is beyond their experience or the accumulated experience of their research library and will network with other conservators to find a solution, or refer an artifact to a more specialized laboratory.

7. All Work Should Be Documented In the long view of things even the best conservation methods are probably no more than temporary fixes. Even the most stable artifact may undergo changes in storage. Few conservators would be foolish enough to guarantee their treatments will continue to stabilize an artifact forever; chemical agents break down over time with minute variations in humidity, light intensity or handling. This is another strong argument for corollary number two, that all conservation techniques should be reversible. The first step in re-treating an artifact would be the removal of whatever remains of the original stabilizing or coating material. Conservation documentation, or the idea of recording all of the steps used to store, clean, and treat an artifact is a vital step in its life long curation. This will allow conservation technicians to plan further conservation treatment and reverse any adverse affects of the original treatment attempt.

8. Normal Artifact Aging Should Not Be Disguised or Removed As far as possible original dyes, paints, inks, stains, gilding, wear marks, tool marks, the macro, and micro-structure of an artifact, should not be changed or removed. Decayed parts of an artifact should be stabilized and conserved, not replaced. If it is necessary to replace a section of an artifact for mechanical strength

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or stabilization, it should be done of material that can easily be removed and contrasts in color or texture significantly from the original artifact in order that observers not mistakenly conclude the artifact is intact. These principles guide the choice of conservation technique and procedure at a minimal intervention laboratory and should allow conservators to treat artifacts against decay while also protecting themselves and the environment. These codes also act as a filter from which the hundreds of treatments available can be reduced to only those few that meet the needs and obligations of the minimal intervention laboratory. If another principle is needed to supplement the first eight, it would be that conservation is 50% informed inventiveness and 50% common sense.

WET LAB—ARTIFACTS ENTER Minimal intervention artifact conservation facilities can be fabricated virtually anywhere or of any size building or room so long as there is adequate floor space to meet the design needs of the lab. Regardless of the size of the laboratory it is usually necessary to divide whatever space is available into Dry Lab Facilities and Wet Lab Facilities in order to separate the two major environmental components of conservation. Most household kitchens would make adequate labs and already contain most of the tools and equipment necessary for minimal intervention conservation. The hypothetical laboratory shown in Figure 1 could be described as no more than a kitchen (Dry Lab Facility) and a garage or storage area (Wet Lab Facility). Generally speaking, artifacts are brought from the field into the Wet lab facility for storage, cleaning, and treatment, after which they pass to the dry lab facility for dehydration and protective coating. Most conservation treatments use three stages depending on material type. The first is a deep cleaning or sometimes an electro-chemical cleaning of an artifact. This removes contaminants from the interior as well as the surface of an object. Neutral chemical agents are at times added to maintain an object’s shape. Finally applications of consolidants and protectants strengthen the artifact and guard against further oxidation or hydration. Most of the deep cleaning and the introduction of bulking and impregnating agents to maintain an artifact’s shape are procedures done in the wet lab. An examination of the wet lab facilities in Figures 1 & 2 (pages 10 and 11) reveals that most of the area is occupied by artifact pre-treatment storage. Metallic artifacts and those recovered from wet environments need to be kept wet in a stabilizing solution while non-metallic artifacts recovered from dry environments need to be kept dry until treatment commences. Laboratories that will treat both wet and dry recovered material will need both tanks and dry shelf storage. Nearly any type of tank will do for wet artifact storage including plastic or galvanized metal. Agricultural feed troughs can be large and cost effective. It should be noted that if artifacts are stored in metal tanks that the tank should be lined in plastic or the artifacts placed in non-conductive containers to prevent


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galvanic coupling (see Chapters 3, 4, and 5). Galvanic coupling occurs when two dissimilar metals come into contact to create corrosion via electron transfer. Metal tanks are also easier to maintain if they are raised above the floor on wooden, cinder block, or brick platforms to prevent corrosion induced by floor spills and cleaning. Shelving should be strong, stable and fastened to a wall or floor to prevent accidental destruction of stored artifacts. Though any material will do for shelving it should be noted that use of metal shelving will require that metal artifacts be placed on non-conducting platforms of wood or plastic. Artifacts should not touch other artifacts while in pre-treatment storage and should generally be organized by material type. The second largest space used in the wet lab is for sinks and workbenches. This also includes space set aside outdoors for concretion removal and rough artifact cleaning, a particularly dirty task best done well away from the rest of the facility. The compressor is used to operate air scribes and bead blasters, two very good methods for mechanically cleaning metals. If floor space is at a premium, vertical air compressors take up little space. Running water is essential in the wet lab to fill storage and treatment tanks. Running water is also essential in many of the rinsing processes that take place in the wet lab. Water is one commodity the wet lab cannot have too much of. The wet lab facilities on page 10, have four types of water, all of which are useful in various treatments. Tap water can be used in initial rinses and for cleaning the facility (a never-ending task in itself). But tap water contains varying amounts of chlorine (depending on the municipality). Chlorine or chloride ions, even in small amounts, are particularly destructive in the breakdown of certain materials including metals, ceramics, and organics. Rinsing chlorides from artifacts is a large part of many treatment processes. Therefore, both distilled and deionized water are manufactured in the wet lab and stored in containers for ready use. Distilled and deionized water are virtually interchangeable in many rinse processes since they both contain very few chloride ions. Both can be manufactured with elaborate scientific equipment or by fairly simple arrangements. Deionized water is produced by filtering tap water through a deionizing unit that consists of a plastic cartridge in which tap water is introduced at one end and deionized water emerges from the other. These units are cheap, simple to operate, and are available through scientific equipment catalogues. Stills to produce distilled water are also available through scientific equipment catalogues but tend to be expensive. An alternative is to collect the water produced by a dehumidifier or air conditioning unit. This water, depending on the cleanliness of the coils in the unit, is virtually chloride free and will suit the purposes of minimal intervention lab for a fraction of the cost of distilling water. Another low chloride water source is rainwater. Rainwater tends to contain some chlorides (in coastal areas), but not nearly the amount found in most tap water. Rainwater is free, and acts as a good intermediate phase rinse solution between tap water and deionized and distilled water. Cisterns to catch rainwater

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are easily constructed of a plastic barrel situated at the bottom of a roof’s gutter and rainspout. Solvent storage for acetone and denatured or methyl alcohol will also be needed in either the wet or dry lab facilities. Solvent storage is subject to building and chemical codes and may need to be stored in a flame resistant metal locker designated to hold flammable liquids. It can also be contained in portable flammable liquid containers with the contents clearly marked on both the cabinet and the container. Additional needs of the wet lab include a vapor proof ventilation system that pulls fresh air into the lab and exhausts the internal air outside. The ventilation system does not have to be powerful, just strong enough to circulate the laboratory air on a regular basis. Minute amounts of hydrogen and oxygen are given off during the electrolytic rinsing process for metals. Though the amounts of these gases given off are negligible their concentration in one area could prove explosive should there be a trigger. Smoking and production of flame of any kind should be discouraged in the wet lab. The hypothetical facilities on page 7 contain some equipment that a minimal intervention facility may not need, but are deemed extremely useful. For example, a MIL can do without a compressor with bead blasting and air scribe capabilities, this type of work can be done with time and effort using hand tools (dental picks, scalpels, or an electric scribe), it is simply much more convenient and cost effective to operate the compressor and its accessories if they are available. Labs often start as bare-bones facilities and upgrade when funding becomes available. A lift for heavy artifacts and a means to carry heavy bags of electrolyte or barrels of bulking agent will also be convenient. Hydraulic engine hoists for heavy artifacts and hand trucks are economical and more than sufficient to move supplies. Those unfamiliar with artifact conservation are often surprised to find that some areas of an artifact conservation facility are far removed from the stereotypical laboratory and create a setting more akin to a factory. In this environment common sense concerning the movement and storage of both artifacts and conservation supplies is a must. Common sense must also apply to layout and organization of the wet lab both for the efficiency of the lab and the safety of the conservation technicians working there. Storage of supplies is not shown in the hypothetical wet lab diagram, and of course it is completely dependent on the facility but much can be done in any lab to cut down inefficiency by removing redundant chemicals and recycling others. Chemicals and bulking agents such as polyethylene glycol and sucrose can be reused time and again. The Bulking Agent Recovery Tank (BART) and storage system shown below will recycle PEG and sucrose multiple times. BART is a large system but it demonstrates how a similar yet smaller system could be used at a minimal intervention lab to recover and recycle valuable bulking agent, while at the same time limiting the amount of storage space needed for chemical agents. Finally the Bulking or Impregnation Treatment Tank can be fabricated from a metal agricultural tank wrapped outside in foil bubble wrap insulation and


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Figure 3. The Bulking Agent Recovery Tank (BART) system at the artifact laboratory, Program in Maritime Studies, East Carolina University. Bulking and impregnating agents are filtered, pumped into the central tank where the water is evaporated through a central vent fan. The agents are then gravity feed to storage tanks on either side of the evaporation tank. PEG and sucrose can be used for many years. Photograph by Chris Valvano.

supported off the floor on wooden blocks or pallets. Wooden artifacts will soak in bulking or impregnating agents for up to a year duration as they absorb a specific amount of PEG or sucrose. Though the tank will work simply by placing the artifacts and chemical in it, it will work faster and more efficiently if it is heated, circulated, insulated, and covered. Scientific heaters and circulators are available for this purpose at tremendous cost. Alternative heaters and stirring devices are easily obtained through the imaginative use of restaurant sink heaters, waterbed heaters, and fish tank filters. Other very usable stirring devices include electric fish trolling motors; inexpensive to buy, reliable for years, and easily powered by a10 amp battery charger. For safety sake the leads to the trolling motor should be spliced permanently into the battery charger cables; positive to positive (red) and negative to negative (black). When artifacts have been cleaned and treated in the wet lab it is time for their transfer to the dry lab for final treatment and dehydration. The two-lab concept is simply that:—a concept. In reality the two labs can be in the same room or the same building, it is the atmospheric separation of processes that is most important and easily brought about by physical separation.

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DRY LAB FACILITIES—ARTIFACTS FINISHED The dry lab facilities depicted in Figure 1 are required to dehydrate, consolidate, and place a protective coating on objects that have been deep cleaned and treated in the wet lab. The dry lab is also the area where an artifact can be closely examined for maker’s marks, fabrication detail, wear patterns, and other micro-excavation details. A magnification table complete with 3X lighted magnification lens and microscope is a necessity for careful examination of artifacts but not completely necessary for the conservation and stabilization of an artifact. A balance beam is also a convenient tool to weigh artifacts during analysis and is perhaps more a conservation necessity than either of the aforementioned items. Yet all of these instruments are very useful and by necessity have to remain separate from the damp and sometimes dusty conditions that prevail in the wet lab. Should space and equipment be available some additional but non-essential facilities could include offices, a dark room, bathroom, artifact storage, a wood shop, a classroom and library, and separate microscope lab. The heart of the dry lab facilities is the enigmatic stove and oven that combine with the freezer refrigerator to give the facility its kitchen like atmosphere. In academic settings the stove and oven are being replaced with scientific versions that serve the same function at many times the expense. The range hood is also being replaced with a scientific fume hood. The oven will be used to dehydrate metals and desiccate other material while the burners will be used to melt microcrystalline wax used to dehydrate and coat metals. The refrigerator acts as a store for recovered organic material while the freezer will be used to freeze-dry selected organic and other pre-treated artifacts. The vaunted vacuum freeze drying systems, seen in the 1980s as magic conservation bullets, proved expensive and only as successful as their pre-treatment, certainly little better in practical terms than atmospheric freeze-drying. In theory freeze-drying allows frozen water in an object to evaporate gradually through sublimation, turning directly from a solid to a gas. Sublimation bypasses the liquid phase that creates so many problems for artifacts (see Chapter 2 and 7 waterlogged Wood and Organics Other than Wood). Vacuum freeze-drying never lived up to its potential and its initial costs are prohibitive for a minimal intervention laboratory. Less expensive equipment such as the Relative Humidity Chamber (RHC) has demonstrated very good results in the dehydration of pre-treated wood and organic material. The relative humidity chamber can be built in house, at a fraction of the cost of a vacuum freeze-dryer. The RHC dehydrates pre-treated organic material and wood by allowing it to slowly dry. Slow drying after a pre-treatment in bulking or impregnating agents lessen the effects of sudden drying (see Chapter 2 Waterlogged Wood) and permits a gradual reintroduction of the artifact to a normal atmosphere. A relative humidity chamber can be any sort of large container, preferably plastic, that can be opened to receive an artifact and then sealed to contain humidity. A plastic agricultural tank cut out and fitted with a shower curtain over the door works well. Ideally


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the chamber would contain a humidifier that can be turned on from outside the chamber (operation of the chamber is explained in Chapter 2). The Hot-Box is another specialized piece of equipment that is easily fabricated from an old refrigerator or freezer that no longer works. A light bulb is installed in the hot box that acts as a heat source. Temperature control is a matter of adjusting the light bulb wattage, the higher the wattage the hotter the box. The Hot-Box will work well for bulking smaller wooden or organic objects that don’t need the large volume treatment tank located in the wet lab. Chemical storage is essential in the dry lab. Acids or oxidizing agents are located on separate shelving from reducing agents (bases) to lessen the chance that a spill will result in disaster. Storage shelves for these chemicals are also strong and secured to the wall or floor. All chemical containers on the shelves of these storage units should be clearly marked for content and rest in chemically resistant spill trays in case of leakage.

SAFETY Safety in the conservation laboratory is largely a matter of common sense, organization, and tidiness. Safety issues at the minimal intervention laboratory are not as great as those in more sophisticated laboratories. But safety does remain an issue even at a minimal intervention lab with few toxic substances. This is particularly true since falls and eye injuries remain the largest type of accident reported in a lab. An uncoiled hose, or a beaker filled with a solvent placed on the edge of a counter top can always be a problem given the proper unlucky circumstances. Fortunately, proper safety habits can cut down on the risks and accidents can usually be avoided before they happen with proper common sense habits, like picking the place up after work has been done. The first safety rule in any lab is the wearing of safety glasses. Safety glasses not only protect the wearer from injury from direct flying objects, but perhaps most importantly, from objects that are flying from unknown angles. This is particularly important in a small lab where the actions of one technician flaking concretion can easily injure another technician nearby. Eye wash stations are also a must in both the dry and wet lab. These can be inexpensive portable units that hang in clearly marked wall spaces or they can be built into the plumbing of the laboratories themselves. Rubber gloves, protective coveralls, and breathing masks are also a good idea depending on the processes and chemicals that are being handled. Even a low toxicity lab will contain some chemicals or solvents that can irritate eyes, skin or throat. In the end it is a good habit to treat all chemicals and substances in the lab with respect and care. Sloppy technicians will injure unintentionally by spilling substances and not cleaning after themselves. The next technician will unwittingly rub their eye after encountering a days old spill. Cleanliness is the second safety rule at the minimal intervention lab.

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Every laboratory should maintain an inventory of every chemical on site. Data sheets for these chemicals can be obtained from the health and safety unit assigned to your lab and Material Safety Data Sheets (MSDS) will be issued for each of these chemicals. The MSDS will list the toxicity and characteristics of these chemicals and should be consulted should any questions arise concerning a substance that will be used or should a technician attempt a new procedure. Posting and use of the MSDS is rule three. Fire extinguishers are placed at strategic points in both labs and near each clearly marked exit. Properly trained safety technicians will check fire extinguishers on a regular basis and their inspection dates posted on the fire extinguisher. Melted wax treatments on the stove will be under continual surveillance from the technician performing the procedure and the stovetop can NEVER be left on while unattended. Where possible in this manual safety issues will be brought up in the general discussion of treatment procedure but no manual or warning can take the place of common sense in both the arrangement and operation of a laboratory. Safety is also an ongoing issue that is enhanced with the continual feed back of the technicians working in a lab. It does no good to observe a problem without suggesting a solution and acting on it. It is a cliché, but safety in a laboratory is the responsibility of every person that walks in the door.

CREATING THE MINIMAL INTERVENTION LABORATORY The suggestions outlined in this chapter are intended as a general guide, not as a technical plan to create a laboratory. Imagination, know-how, and common sense will permit conservation technicians to create or add laboratory space and capability as they see fit or as money and time permit. The theoretical minimal intervention laboratory diagramed in Figure 1 and described in this chapter is simply a pattern or model, just as The Archaeologist Manual for Conservation is a tool. A laboratory is always more a process than a structure. It grows and changes as the conservators and technicians gain experience and knowledge, or as is often the case; when they have to grow to support the expanding needs of an archaeological program. It is hoped this manual will give conservation technicians and conservators a new instrument from which they can expand their concept of conservation and implement new conservation techniques or refine those already in place. Vast numbers of archaeological artifacts lie in storeroom boxes, seemingly out of sight and out of mind, but few have truly been stabilized through surface cleaning and storage. This manual should permit archaeological conservators to reevaluate conservation at their laboratories add new techniques and methodology to their repertoire of procedures, or create a facility capable of conserving artifacts recovered from virtually any site environment.


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BIBLIOGRAPHY The minimal intervention laboratory concept is simplistic but not easily implemented. Its underpinnings begin with comprehensive accumulated research, represented in this manual in the form of bibliographies located at the end of each chapter. This chapter’s bibliography contains general archaeological conservation sources including all of the new and classic conservation texts, plus accumulated articles and technical notes gleaned from technical journals and periodicals. Succeeding chapter bibliographies contain books and articles concerned only with the type of material covered in that chapter.

CHAPTER 1: THE MINIMAL INTERVENTION LABORATORY Abinion, Orlando V. “The Recovery of the 12th century Wooden Boats in the Philippines.” Bulletin of the Australian Institute for Maritime Archaeology 13 (1989): 1–2. Allison, Rutherford. “Infrared Photography Using an Ultraviolet Radiation Source.” Medical and Biological Illustration. Vol. 27, 1977: 35–36. [ECU-521] Anon. Archaeological Conservation Newsletter. (South Carolina State Museum Conservation Laboratory Publication.) 2 (January 1990). [ECU-344] Anon. “Conservation in Archaeology and the Applied Arts.” ICOM Congress. Stockholm, (1975). Anon. “Fabric Protects Historic Ship.” Textile Month (1983): 23. [ECU-217] Anon. “On Site Conservation Requirements for Marine Archaeological Excavations.” International Journal of Nautical Archaeology 6 (1977): 37–46. Anon. “Underwater Treasures Under the Microscope: Objects from the DeBrack Analyzed at Winterthur.” Winterthur Newsletter 34 (n.d.): 14–15. Applebaum, Barbara. “Comments from a Conservator on Climate Control.” WAAC Newsletter Vol. 18 No. 3, 1996. [ECU-749] Arthur, B.V. “The Conservation of Artifacts from the Wreck Machault.” ICOM Proceedings (3rd Triennial Meeting, Madrid) (1971). Ashley-Smith, Jonathan. Risk Assessment for Object Conservation. London: Elsevier, 1999. Barclay, Robert. “The History of Conservation: The Contribution of Michael Faraday.” CCI Newsletter (Canadian Conservation Institute, Ottawa) No. 29, 2002. [ECU-612] —. “Mrs. Beeton, Household Conservator.” CCI Newsletter (Canadian Conservation Institute, Ottawa) No. 28 2001. [ECU-613] —. “Staying in Tune with Conservation.” CCI Newsletter (Canadian Conservation Institute, Ottawa) No. 22 1998. [ECU-614] Barkman, L. “Conservation of Finds.” Proceedings (First Southern Hemisphere Conference on Maritime Archaeology) (1978): 119–120. —. “Inventory of Ancient Monuments Underwater in Sweden.” Proceedings (First Southern Hemisphere Conference on Maritime Archaeology) (1978). —. “Treatment of Waterlogged Finds.” Proceedings (First Southern Hemisphere Conference on Maritime Archaeology) (1978): 120–126. —. “The Conservation of the Waterlogged Warship Wasa.” Proceedings (ICOMOS Symposium on the Weathering of Wood, Ludwigsburg.) (1969): 99–106. —. “The Preservation of the Warship Wasa.” Maritime Monographs and Reports (National Maritime Museum, Greenwich, U.K.) 16 (1975), 65–105. [ECU-251] —. “Treatment of Waterlogged Finds.” Proceedings (First Southern Hemisphere Conference on Maritime Archaeology) (1977): 120–126.

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—. The Preservation of the Wasa. Stockholm Museum, 1967. Barkman, L. and A. Frantzen. “ The Wasa: Preservation and Conservation.” Underwater Archaeology, A Nascent Discipline (UNESCO) (1972): 231–242. Bass, George F. “ The Shipwreck at Serce Limon, Turkey.” Archaeology 32 (1979): 36–44. [ECU-0270] Bengtsson, Sven. “What about Wasa? ” Realia 1 (1990): 309–311. Berrett, Kory. “Conservation Surveys” Ethical Issues and Standards.” Journal of the American Institute for Conservation. Vol. 33 No. 2, 1994, pp. 193–198. [ECU615] Black, J., ed. Recent Advances in the Conservation and Analysis of Artifacts. (Jubilee Conservation Conference Papers. University of London, Institute of Archaeology, Summer Schools Press, London) (1987). —. “The Biodeterioration and Conservation of Archaeological Materials Symposium.” (Abstracts, University of Portsmouth, Portsmouth) (September 1992). [ECU-435] Borden, C.E. Excavation of Water Saturated Archaeological Sites. Natural Museums of Canada 1976. Borgin, K. “Mombasa Wreck Excavation: Second Preliminary Report, 1978. Appendix 2: Progress Report on Evaluating the Thessaloniki Process.” International Journal of Nautical Archaeology (1978): 301–319. Bourque, B.J., S.W. Brooke, R. Kley, and K. Morris. “Conservation in Archaeology: Moving Toward Closer Cooperation.” American Antiquity 45:4 (1980): 794–799. Bried, Raymond. “She Wasn’t Made to be Taken Apart.” Yankee (1973): 84–93, 106–111. Bright, Leslie S., W.H. Rowland, and I.C. Bardon. “Preservation of the Neuse, Appendix l.” A Question of Iron and Time (North Carolina Division of Archives and History) (1981). [ECU-16] Brooke, S. and K. Morris. “A Preliminary Report on the Conservation of Marine Archaeological Objects from the Defense.” (Bulletin of the American Institute for Conservation, Preprints, Boston) (1977): 27–34. Buck, Richard. “On Conservation.” Museum News 52 (1973): 15–16. [ECU-327] Bump, Herbert D. “Report Concerning the Condition of Artifacts at the Confederate Naval Museum, Columbus, Georgia.” (Research amd Conservation Laboratory Monograph, Florida Department of State) [n.d.] [ECU-0376] Byung-Mo, K., K. Ki-Woong, and P.H. Kieth. “ The Shinan Shipwreck.” Museum 35 (1983): 35–37. Canadian Conservation Institute. Annual Report 1995–1996. Canadian (1996). [ECU-527] Canadian Conservation Institute. Annual Report 1994–1995. Canadian (1995). [ECU-554] Canadian Conservation Institute. Annual Report 1993–1994. Canadian (1994). [ECU-519] Canadian Conservation Institute. Catalog of Publications. 1995. [ECU-555] Canadian Conservation Institute. CCI Newsletter September 1996, No. 18. [ECU-528] Canadian Conservation Institute. CCI Newsletter (1987–present). [ECU-298] Canadian Conservation Institute. CCI Newsletter March 1997, No. 19. [ECU-586] CCI Laboratory Staff. “Encapsulation.” CCI Notes (Canadian Conservation Institute) 11/10 (1995). [ECU-543] CCI Laboratory Staff. “Emergency Preparedness for Cultural Institutions: Introduction.” CCI Notes (Canadian Conservation Institute) 41/1 (1995). [ECU-547] CCI Laboratory Staff. “Emergency Preparedness for Cultural Institutions: Identifying and Reducing Hazards” CCI Notes (Canadian Conservation Institute) 14/2 (1995). [ECU-548] CCI Laboratory Staff. “Planning for Disaster Management: Introduction.” CCI Notes (Canadian Conservation Institute) 14/1 (1988). [ECU-443] CCI Laboratory Staff. “Precautions for Storage Areas.” CCI Notes (Canadian Conservation Institute) 1/1 (1992). [ECU-458] CCI Laboratory Staff. “Time Capsules.” CCI Notes (Canadian Conservation Institute) 1/6 (1995). [ECU-535] CCI Laboratory Staff. “Track Lighting.” CCI Notes (Canadian Conservation Institute) 2/3 (1992). [ECU-459] CCI Laboratory Staff. “Using a Camera to Measure Light Levels.” CCI Notes (Canadian Conservation Institute) 2/5 (1992). [ECU-460]


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CCI Laboratory Staff. “CCI Environmental Monitoring Equipment.” CCI Notes (Canadian Conservation Institute) 2/4 (1993). [ECU-471] CCI Laboratory Staff. “Ultraviolet Filters.” CCI Notes (Canadian Conservation Institute) 2/1 (1994). [ECU-472] CCI Laboratory Staff. “The Diphenylamine Spot Test for Cellulose Nitrate in Museum Objects.” CCI Notes (Canadian Conservation Institute 17/2) (1994). [ECU-509] Carrell, Toni L., ed. Underwater Archaeology Proceedings (Society of Historical Archaeology Conference, Tucson, Arizona) (1990). “Conservation in Archaeology and the Applied Arts.” ICOM Congress (Stockholm) (1975). “Conservation Center Stage” Museum News Vol. 76, 1997, pp. 48–49, 59–63. [ECU-750] “Conservation in Nautical Archaeology.” INA Newsletter Vol. 6 No. 1, Spring 1979. [ECU-579] Cornet, I. Scientific Methods in Medieval Archaeolgy. Sacramento: University of California Press, 1970. Costain, Charles. “The Light Damage Slide Rule.” CCI Newsletter (February, 1989): 19. [ECU-24] Cowan, Rex, Z. and Peter Marsden. “The Dutch East-Indiaman Hollandia Wrecked on the Isles of Scilly in 1743.” International Journal of Nautical Archaeology 4 (1975): 267–300. [ECU-380] Cronyn, J.M. The Elements of Archaeological Conservation. London: Routledge, 1990. [ECU-350] Daley, Thomas W. and Lorne D. Murdock. “Excavating and Raising Artifacts from a Marine Environment.” [ECU-556] —. “Underwater Molding of a Cross Section of the San Juan Hull—Red Bay, Labrador.” ICOM 7th Triennial Meeting, Sept. 1984. [ECU-526] Daugherty, R. “Responsibilities and Commitment in the Excavation of Wet Sites.” Proceedings (International Conference on Wet Site Archaeology, University of Florida, Gainesville) (1986). Davies, P.N. “The Discovery and Excavation of the Royal Yacht Navy.” Maritime Wales (1978): 25– 32. Davison, S. “Antiquities.” Adhesives and Consolidants, Reprints of the Contributions to the Paris Congress 2–8 Sept. 1984. IIC London, 1994. [ECU-563] Dawson, John E. and Thomas J.K. Strang. “Controlling Vertebrate Pests in Museums.” CCI Technical Bulletin (Canadian Conservation Institute, Ottawa) 13 (1991). [ECU-375] Dawson, John E. and Thomas J.K. Strang. “Solving Museum Insect Problems: Chemical Control.” CCI Technical Bulletin (Canada Conservation Institute, Ottawa) 15 (1992). [ECU-434] “Dechlorination in Buffered Citrate.” [ECU-587] Degrigny, Christian. Bulletin of the Research on Metal Conservation. ICOM Metal Working Group, February 2003. [ECU-608] “Description and Evaluation of Florida State Preservation Laboratory.” [ECU-588] Denton, Mark H. and Joan S. Gardner. “Recovery and Conservation of Waterlogged Goods from the Well Excavated at the Fort Loudon Site, Fort Loudon, Pennylvania.” Historical Archaeology 17:1 (1983): 97–103. [ECU-382] De Jong, J. “The Conservation of Shipwrecks.” ICOM Proceedings (Zagreb) (1978). —. “Protection and Conservation of Shipwrecks.” Greenwich Archaeological Series No. 5 (National Maritime Museum, British Archaeology Reports, International Series 66) (1979): 1–10. De Jong, J., W. Eenkhoorn, and A.J.M. Wevers. “Controlled Drying as an Approach to the Conservation of Shipwrecks.” ICOM-WWWG Proceedings (Ottawa) (1981): 1–10. Doran, Glen H., and David N. Dickel. “Multidisciplinary Investigations at the Windover Site.” Proceedings (First International Conference on Wet Site Archaeology, University of Florida, Gainesville) (1986). Doroman, E.A. Conservation in Field Archaeology. London: Metheun, 1970. —. The Excavation of Water-Saturated Archaeological Sites (Wet-Sites) on the Northwest Coast of North America (Archaeological Survey of Canada Mercury Series, No. 50, National Museum of Canada) (1976). Down, Jane L. “CCI Analysis Aids Conservation of the Archimedes Palimpsest.” CCI Newsletter (Canadian Conservation Institute) No. 28, 2001. [ECU-617]

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Erhardt, David and Marion Mecklenburg. “Relative Humidity Re-Examined” Ottawa Congress of the IIC, 1994. [ECU-751] Erhardt, David, Marion F. Mecklenburg, Charles S. Tumosa, Mark McCormick—Goodhart. “The Determination of Allowable RH Fluctuations” Smithsonian Magazine Vol. 17 No. 1, 1995. [ECU-752] The Excavation of Water-Saturated Archaeological Sites (Wet-Sites) on the Northwest Coast of North America, Archaeological Survey of Canada Mercury Series, No. 50, National Museum of Canada (1976). —. “The Determination of Appropriate Museum Environments.” British Museum Occasional Paper Num. 16, pp. 153–163. [ECU-753] Fawcett, Jane ed. Historic Floors, their Care and Conservation. London: Elsevier, 2001. Feilden, Ernard. Conservation of Historic Buildings. London: Elsevier, 2003. Feller, Robert. “Aspects of Chemical Research in Conservation: The Deterioration Process.” Journal of the American Institute for Conservation. Vol. 33 No. 2, 1994. [ECU-618] Ferrier, R.J. and P.M. Collins. Monosaccharide Chemistry. London: Penguin Books, 1972. Folan, W.J., J.H. Rick, and W. Zachaschuck. “The Mechanization of Artifact Processing.” American Antiquity 33 (1968): 86–89. Florian, M-L. E. “The Underwater Environment.” [ECU-590] “Freeze Drying Services.” Hackettstown, NJ: The Artifact Research Center. [ECU-591] Fruter, E.V. Introduction to Natural Protein Fibers: Basic Chemistry. New York: Barnes and Noble, 1973. Gannon, Robert. “What Really Sank the Titanic?” Popular Science. Feb. 1995: 49–55, 83. [ECU-522] Garfield, Donald. “Hot Topic, Cool Reception.” Museum News, 1995. [ECU-754] Garcia-Vallés, F. Blazquez, J. Molera, and M. Vendrell-Saz. “Studies of patinas and Decay Mechanisms Leading to the Restoration of Santa Maria de Montblanc (Catalonnia, Spain)” Studies in Conservation. Vol. 41 No. 1, 1996. [ECU-619] Gilliand, Marion S. “Marco’s Buried Treasure: Wetlands Archaeology and Adventure in Nineteenth Century Florida.” Wet Site Archaeology B.A. Purdy, ed., (1988): 255–261. Gould, Donald. “Draining the Zuider Zee Uncovers a Boneyard of Ancient Ships.” Smithsonian 5 (1974): 66–73. [ECU-276] Graham-Bell, Maggie. Preventative Conservation: A Manual. Victoria, British Columbia: British Columbia Museums Association, 1983. [ECU-1] Grattan, David. “New Directions in Education for Marine Archaeological Conservation.” CCI Newsletter (Canadian Conservation Institute) No. 28, 2001. [ECU-620] Green, Jeremy N. “Field Conservation in Marine Archaeology: A Consumer’s View Point.” Proceedings (National Seminar on Cultural Material, Perth, Australia) (1976): 195–197. —. “The VOC Ship Batavia Wrecked in 1629 on the Houtman Abrolhos, Western Australia,” International Journal of Nautical Archaeology 4 (1975): 43–63. [ECU-164] Green, Lorna R. and Vincent Daniels. “Shades of the Past.” Chemistry in Britain Vol. 31 No. 8, 1995. [ECU-656] Greenhill, Basil. “Vessel of the Baltic: The Hansa Cog and the Viking Tradition.” Country Life (1980): 402–404. [ECU-132] Groen, C. “The Use of Tomography in the Analysis of Maritime Archaeological Material.” Proceedings (First Southern Hemisphere Conference on Maritime Archaeology) (1978): 144–145. Gulbeck, Per E. The Care of Antiques and Historical Collections. American Association for State and Local History, 1985. [ECU-3] Gutierrez, Gilles. Texinfine Product Brief (French Ministry of Research and Technology, Lyon, France) [n.d.] [ECU-379] Hallowall, C. “Disappearance of the Historic Ship Tijger,” Natural History 83 [n.d.]: 12–28. [ECU158] Hamilton, Donny L. “Preliminary Report on the Archaeological Investigation of the Submerged Remains of Port-Royal, Jamaica, 1981–1982.” International Journal of Nautical Archaeology 13 (1984): 11–15.


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—. “Conservation of Cultural Resources, I.” (Class Handouts for ANTH 605, Texan A&M University, Nautical Archaeology Program, August) (1988). [ECU-364] —. Basic Methods of Conserving Underwater Archaeological Material Culture. Washington, D.C.: U.S. Department of Defense Legacy Resource Management Program, January 1996. [ECU-610] Harrison, R.F. “ The Mary Rose Tudor Ship Museum.” Museum (France) 35 (1983): 44–49. Hauser, Robert, “Technology Update: Enzymes in Conservation—A Conference Report,” Technology and Conservation, Vol. 11 No. 4 (Winter 1992–93): 13–15. Hay, James. “The History of Conservation: Furniture Polishes.” CCI Newsletter (Canadian Conservation Institute) No. 27, 2001. [ECU-621] Hon, David N.S. “An Implementation Strategy for Stabilization of the U.S.S. Cairo.” (Progress Report, No. CA-5000-4-8003, College of Forest and Recreation Resources, Clemson University) [n.d.] [ECU-377] Horie, C.V. Materials For Conservation. London: Elsevier, 1987. Hough, Mary Piper. “What are Appropriate Standards for the Indoor Envrionment, Review of Symposium.” WAAC Newsletter Vol. 17 No. 3, 1995. [ECU-755]Hurt, Joseph L. “Preliminary Report: Preservation of the CSS Muscogee.” (Georgia Historical Commission) (1966): 1–14. [ECU-42] ICOM Committee for Conservation Working Group on Wet Organic Archaeological Materials Newsletter. Nos. 25, 28, 31, 32. [ECU-593] Iskander, Z. The Cheops Boat, Part 1. Cairo: Antiquities Department of Egypt, 1960. Jenssen, V. and Colin Pearson. “Enviromental Considerations for Storage and Display of Marine Finds.” Conservation of Marine Archaeological Objects C. Pearson, ed., (1987): 268–270. [ECU-6] Johnson, Jessica. “Conservation and Archaeology in Great Britain and the United States: A Comparison” Journal of the American Institute for Conservation. Vol. 32 No. 3, 1993. [ECU-622] Johnson, Stuart. “Alternatives for the Continued Preservation of the U.S.S. Cairo.” (Office of Cultural Resources Monograph, National Park Service, Southeast Region) [n.d.] [ECU-0378] Jokilehto, Jukka. History of Architectural Conservation. London: Elsevier, 2002. Kadry, Ahmed. “ The Solar Boat of Cheops.” International Journal of Nautical Archaeology 15 (1986): 123–131. [ECU-154] Katzev, Michael L. “Conservation of the Kyrenia Ships, 1970–7l.” National Geographic Society Research Reports (1979): 331–340. —. “Conservation of the Kyrenia Ships, 1971–72.” National Geographic Society Research Reports (1980): 417–426. Katzev, Susan W. and Michael L. Katzev. “Last Harbor for the Oldest Ship.” National Geographic 146 (1974): 618–625. [ECU-173] Keene, Suzanne. Digital Collection, Museums in the Information Age. London: Elsevier, 1998. Kernan, Michael. “Around the Mall and Beyond.” Smithsonian Magazine Vol. 18 No. 3, 1996. [ECU-756] Kertish, P.J. “The Conservation of Marine Artifacts for the Professional Conservator.” Heritage Australia 2 (1983): 62–65. Kimble-Brown, M. “A Preservative Compound for Archaeological Material.” American Antiquity 39 (1974): 469–473. [ECU-110] Kvaming, L.A. “ The Wasa: Museum and Museum Exhibit,” Museum 36 (1984): 75–80. Lafontaine, Raymond. “Recommended Environmental Monitors for Museums, Archives, and Galleries.” CCI Technical Bulletin 3 (Canadian Conservation Institute) (1980). [ECU-453] Lafontaine, Raymond. “Silica Gel.” CCI Technical Bulletin 10 (Canadian Conservation Institute) (1984). [ECU-450] Lafontaine, Raymond H. and Patricia A. Wood. “Fluorescent Lamps,” CCI Technical Bulletin 7 (Canadian Conservation Institute) (1982). [ECU-439] Lawson, E. “In-between: The Care of Artifacts from the Seabed in the Conservation Laboratory and Some Reasons Why it is Necessary.” Beneath the Waters of Time (Proceedings of the Ninth Conference on Underwater Archaeology. Texas Antiquities Publication No. 6) (1978): 69–91. Legacy. University of South Carolina. Vol. 6 No. 1, July 2001. [ECU-596]

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Leigh, David. First Aid for Finds. University of South Hampton Press, 1972. Logan, Judith A. and Maureen Williams. “Conservation of Inorganic Archaeological Material.” Proceedings (Canadian Conservation Institute Seminar for Association Museums, New Brunswick Inc., June 25–26) (1991): 1–44. [ECU-373] MacLeod, K.J. “Relative Humidity: Its Importance, Measurement and Control in Museums.” CCI Technical Bulletin 1 (Canadian Conservation Institute) (1978). [ECU-452] MacLeod, K.J. “Museum Lighting.” CCI Technical Bulletin 2 (Canadian Conservation Institute) (1978). [ECU-454] MacLeod, Ian Donald. “Environmental Effects on Shipwreck Material from Analysis of Marine Concretions.” Archaeometry: An Australian Perspective W. Ambrose and P. Duerdin, eds., (1982): 361–367. Maekawa, Shin and Kerstin Elert. The Use of Oxygen-Free Environments in the Control of Museum Insect-Pests. (Review) Getty Conservation Institute. [ECU-597] Maming, Sam. “The Alvin Clark Revisited.” Wooden Boat (1983): 66–68. [ECU-266] Maryland Historical Trust Binder. [ECU-607] McCarthy, Mike. “The S.S. Xantho Project: Management and Conservation.” Proceedings. (ICOM, Fremantle) (1987): 9–15. [ECU-195] —. “S.S. Xantho: The Pre-Disturbance, Assessment, Excavation, and Management of an Iron Steam Shipwreck off the Coast of Western Australia.” International Journal of Nautical Archaeology (1988): 339347. [ECU-128] McCawley, I.C. “Waterlogged Artifacts: The Challenge for Conservation.” Journal of the Canadian Conservation Institute (1977): 17–26. [ECU-580] McCawley, J.C., and T. G. Stone. “A Mobile Conservation Laboratory Service.” Studies in Conservation (1982): 97–106. [ECU-245] McCrady, Ellen. “Indoor Environment Standards: A Report on th e NYU Symposium.” Abbey Newsletter Vol. 19 No. 7, 1995. [ECU-757] McDonald, S. “Sharing Museum Skills at the Maritime Museum, Greenwich.” Scottish Society for Conservation and Restoration Vol. 13 No. 2, pp. 13–14. [ECU-758] McGrath, H.T. Jr. “The Eventual Preservation and Stabilization of the USS Cairo.” International Journal of Nautical Archaeology 10 (1981): 79–94. [ECU-162] Mecklenburg, Marion and Charles Tumosa. “Temperature and Relative Humidity Effects on the Mechanical and Chemical Stability of Collections.” ASHRAE Journal Vol. 41 No. 4, 1999, pp. 77–82. [ECU-759] Michalski, Stefan. “Setting Standards for Conservation : New Temperature and Relative Humidity Guidelines are Now Published.” CCI Newsletter (Canadian Conservation Institute) No. 24, 1999. [ECU-623] Middleton, Andrew and Janet Lang. Radiography of Cultural Material. London: Elsevier, 1997. Moon, Thomas, Michael R. Schilling, and Sally Thirkettle. “A Note on the Use of False-Color Infrared Photography in Conservation.” Studies in Conservation Vol. 37 No. 1, 1992, pp. 42–52. [ECU-653] Muhlethaler, B., Barkman, L., and Noack. Conservation of Waterlogged Wood and Wet Leather. Paris: Edition eyrothes (1973). [ECU-0369] Muhly, J.D., et al. “The Cape Gelidonya Shipwreck and the Bronze Age Metal Trade in the Eastern Medditerranean.” Journal of Field Archaeology 4 (1971): 353–362. Murdock, L.D. and T. Daley. “Polysulfide Rubber and its Application for Recording Archaeological Ship’s Features in a Marine Enviroment.” International Journal of Nautical Archaeology 10 (1981): 337–342. [ECU-163] —. “Progress Report on the Use of FMC Polysulfied Rubber Compound for Recording Archaeological Ship’s Features in a Marine Environment.” International Journal of Nautical Archaeology 11 (1982): 349–353. [ECU-160] Murdock, Lorne D., and John Stewart. Monitoring Program for Shipwrecks at Fathom Five National Marine Park, Tobermoy, Ontario, Canada. Historic Resource Conservation Branch, Parks Canada, 1800 Walkway Road, Ottawa, Ontario, Canada, KIA OM5. [ECU-523]


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Murray, Howard. “ The Conservation of Artifacts from the Mary Rose.” ICOM-WWWG Proceedings (Ottawa) (1981): 3–18. —. “The Conservation of Artifacts from the Mary Rose.” ICOM-WWWG Proceedings (1981): 12–18. [ECU-58] Nasti, Atilio. “Recovery and Conservation of Navigational Instruments from the Spanish Troopship Salvador Which Sank in 1812 in Maldonado Bay, Punta del Este, Uraguay.” International Journal of Nautical Archaeology Vol. 32 No. 2, 2001, pp. 279–281. [ECU-624] Nelson, Daniel A. “An Approach to the Conservation of Intact Ships Found in Deep Water.” ICOMWWWG Proceedings (Ottawa) (1981): 29–32. [ECU-59] Neumann, Thomas W. and Robert M. Stanford. “Cleaning Artifacts with Calgon.” American Antiquity. Vol. 63 No. 1, 1998. [ECU-654] “Nitrogen” Smithsonian Vol. 28 No. 7, 1997, pp. 70–78. [ECU-760] “Observations on Preservation of Archaeological Wrecks of Metal in Marine Environments.” International Journal of Nautical Archaeology 10.1 (1981): 3–14. [ECU-418] O’Donnell, E.B. Oceans of Australia: Papers from the First Southern Hemisphere Conference on Maritime Archaeology (Australia) (1978): 1–160. —. “Conservation of Marine Artifacts from the HMS Culloden.” Proceedings (13th Conference on Underwater Archaeology) (1982): 12. [ECU-65] Oddy, W.A. and P.C. Van Geersdaele. “Lifting and Removal.” The Graveny Boat: A Tenth Century Find from Kent (V. Fenwick, ed., British Archaeological Reports, Oxford) (1975). Oddy, Andrew. “Restoring Faith.” Chemistry in Britain. Vol. 31 No. 8, 1995. [ECU-655] Olive, J. and Colin Peterson. “Conservation in Archaeology and the Applied Arts.” Proceedings of the 1975 Stockholm Conference. IIC London, 1975. [ECU-564] “On Site Conservation Requirements for Marine Archaeological Excavations.” International Journal of Nautical Archaeology 6 (1977): 37–46. “Oxygen, The Great Destroyer.” Natural History Vol. 101 No. 8, 1992, pp. 46. [ECU-761] Padfield, Tim, David Erhardt, and Walter Hopwood. “Trouble in Store.” IIC Washington Congress Proceedings, 1982. [ECU-762] Parker, Henry S. “The Chemistry and Origin of Ocean Waters.” Exploring the Oceans: An Introduction for the Traveler, Amateur, and Naturalist. Englewood, NJ: Prentice Hall, 1985, pp. 82–106. [ECU-532] Parker, Henry S. Exploring the Oceans: An Introduction for the Traveler and Amateur Naturalist. Englewood Cliffs, NJ: Prentice Hall Encyclopedia, 1985. [ECU-598] “Parylene — A Gas Phase Polymer for Conservation of Historical Material.” Nova Tron Corporation, Clear Lake, WI. [ECU-416] “The Parylene Press—Issue 27, Winter 1997” [web site online] Specialty Coating Systems. Available at http://www.scscookson.com/applications/winter97/. [ECU-599] Paterson, E.T., S.M. Mahoney, and K.E. Priydowicz. “ The Conservation of the HD-4: Alexander Graham Bell’s Hydrofoil.” Studies in Conservation 24 (1979): 93–107. [ECU-180] Pearson, Colin. “Conservation and Maritime Archaeology.” International Journal of Nautical Archaeology 9 (1980): 147–150. —. “The Western Australia Museum Conservation Laboratory for Marine Archaeological Material.” International Journal of Nautical Archaeology 3 (1974): 295–305. —. “On-Site Conservation Requirements for Marine Archaeological Excavations.” International Journal of Nautical Archaeology 6 (1977): 37–46. [ECU-71] —. “The State of the Art and Science of Conservation in Maritime Archaeology.” Proceedings (First Southern Hemisphere Conference on Maritime Archaeology) (1978): 116–117. —. “Laboratory Conservation.” Protection of the Underwater Heritage (Technical Handbooks for Museums and Monuments, No. 4, UNESCO, Paris) (1981): 112–113. —. “Conservation of the Underwater Heritage.” Protection of the Underwater Heritage (Technical Handbooks for Museums and Monuments, No. 4, UNESCO, Paris) (1981). [ECU-0007] Pearson, Colin, ed. Conservation of Marine Archaeological Objects, London: Butterworths Series in Conservation and Museology, 1987. [ECU-6]

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Pennec, Stephane, Noel Lacoudre, and Jacques Montlucan. “ The Conservation of Titanic Artifacts.” Bulletin (Australian Institute for Maritime Archaeology) 13 (1989): 23–26. Peterson, M. “The Condition of Materials Found in Salt Water.” Diving Into the Past (Minnesota Historical Society: St. Paul) (1964). —. “Preservation of Material Recovered from Underwater.” (Office of the Chief, Naval Operations, Washington, D.C.) (1965). Petruska-Young, Lisa. “Conservation on a Shoestring: Doing More with Less.” Mid-Atlantic Conference—Ocean City, MD, 1994. [ECU-557] Pipes, Marie-Lorraine. “Zooarchaeology: The Analysis and Interpretation of Faunal Remains from Archaeological Sites.” [ECU-600] Piercy, Robin, C.M. “Mombasa Wreck Excavation: Second Preliminary Report, 1978.” International Journal of Nautical Archaeology 7 (1978): 301–319. [ECU-169] Plenderleith, Harold J. “A History of Conservation.” Studies in Conservation. Vol. 43 No. 3, 1998. [ECU-625] Plenderleith, H.J., and A.E.A. Werner. The Conservation of Antiques and Works of Art. Second edition. London: Oxford University Press, 1971. [ECU-8] Powell, Kathleen, and Patricia Wilkie. “Labeling and Tagging for Artifact Identity Survival.” Proceedings (Pacific Northwest Conference) Vol. 1 (1976): 81–90. [ECU-233] Pournou, A., A.M. Jones, S.T. Moss. “Biodeterioration Dynamics of Marine Wreck-Sites Determine the Need for Their In-Situ Protection.” International Journal of Nautical Archaeology Vol. 30 No. 2, 2001, pp. 299–305. [ECU-626] Price, Stanley, M.P., ed. Conservation on Archaeological Excavations with Particular Reference to the Mediterranean Area. (International Center for the Study of the Preservation and the Restoration of Cultural Deposits, Rome) (1984). [ECU-368] Purdy, Barbara. “The Key Marco, Florida Collection: Experiment and Reflection.” American Antiquity 39 (1974): 104–109. [ECU-108] Purdy, Barbara A., ed. Wet Site Archaeology. Telford Press, West Caldwell, 1988. “Remember the Maine” Smithsonian Vol. 28 No. 11, 1998, pp. 46–57. [ECU-763] Robinson, Wendy S. First Aid for Marine Finds. (Handbook for Marine Archaeology No. 2., National Maritime Museum, Greenwich, U.K.) (1981). [ECUl-296] —. “Observations on the Preservation of Archaeological Wrecks and Metal in Marine Environments.” International Journal of Nautical Archaeology 10 (1981): 3–14 [ECU-78] Rodgers, Bradley A. The East Carolina University Conservator’s Cookbook: A Methodological Approach to the Conservation of Water Soaked Artifacts. Herbert Pascal Memorial Fund Publication, East Carolina University, Program in Maritime History and Underwater Research, 1995. [ECU-402] —. Conservation of Water Soaked Materials Bibliography. 3rd ed. Herbert Pascal Memorial Fund Publication, East Carolina University, Program in maritime History and Underwater research, 1992. Rose, Carolyn L. “Notes on Archaeological Conservation.” Bulletin of the American Institute for Conservation 14/2 (1974): 123–130. [ECU-331] Rule, Margaret. “Legacy From the Deep: Henry VIII’s Lost Warship.” National Geographic 163 (1983): 636–675. [ECU-0272] Rutherford, Allison. “Infrared Photography Using an Ultravoilet Radiation Source.” Medical and Biological Illustration 27 (1977): 35–36. [ECU-521] Sanford, E. “Conservation of Artifacts: A Question of Survival.” Historical Archaeology 9 (1975): 55–64. [ECU-332] Sargent Welch VWR Scientific. Product Catalog. [ECU-602] “Saving Grace” Museum News Vol. 71, 1992, pp. 42–47, 78. [ECU-764] Schneider, Kent A. “X-Ray Radiography in Archaeology.” Southeastern Archaeological Conference, Oct. 1974. [ECU-432] Sease, Catherine. “The Case Against Using Soluable Nylon in Conservation Work.” Studies in Conservation 26 (1981): 102–110. [ECU-221]


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—. A Conservation Manual for the Field Archaeologist. (Archaeological Research Tools Vol. 4, Institute of Archaeology, University of California, Los Angeles) (1987). [ECU-370] Schlichting, Carl. “Working with Polyethylene Foam and Fluted Plastic Sheet.” CCI Technical Bulletin 14 (Canadian Conservation Institute) (1994). [ECU-499] Schneider, Kent A. “X-Ray Radiography in Archeology.” (Unpublished paper presented to the Southeastern Archeological Conference, October 1974) (1974). [ECU-432] Shapiro, L. Dennis. “Computerization of Collection Records.” Technology and Conservation. Vol. 12, No. 3 (Fall 1995): pp. 15–19. Shashoua, Y., S.M. Bradley, and V.D. Daniels. “Degradation of Cellulose Nitrate Adhesive.” Studies in Conservation. Vol. 37 No. 2, 1992. [ECU-627] Sheppard, John C. “Influence of Contaminants and Preservatives on Radiocarbon Dates.” Proceedings (Pacific Northwest Conference) Vol. 1 (1976): 91–96. [ECU-232] Singley, Katherine R. “Caring for Artifacts after Excavation ... Some Advice for Archaeologists.” Historical Archaeology 15:1 (1981): 36–48. [ECU-381] —. The Conservation of Archaeological Artifacts from Freshwater Environments. South Haven, Michigan: Lake Michigan Maritime Museum, 1988. [ECU-10] —. “The Recovery and Conservation of the Brown’s Ferry Vessel.” ICOM-WWWG Proceedings (1981): 57–60. [ECU-86] —. “Archaeological Conservation: Specialized Techniques and Research for Wet Objects.” CCI Newsletter (Canadian Conservation Institute) No. 23, 1999. [ECU-628] Siver, N. “Preparations for Field Conservation.” Scottish Society for Conservation and Restoration Vol. 13 No. 2. [ECU-765] Smith, Clifford. “Santa Lucia Conservation Complete.” Maritimes Vol. 14 No. 1, 2001. [ECU-657] Smith, C. Wayne. Archaeological Conservation Using Polymers Practical Applications for Organic Artifact Stabilization. College Station: Texas A & M University Press, 2003. Smith, James B. and John P. Ellis. “The Preservation of Underwater Archaeological Specimens in Plastic.” Curator 6 (1963): 32–36. [ECU-87] Smith, R.D. “The Relative Hazards of Vapor from Solvents Used by Conservators.” Guild of Bookworkers Journal 11 (Winter 1972–73): 3–9. [ECU-359] “Solving Museum Insect Problems: Chemical Control.” CCI Technical Bulletin (15, Canadian Conservation Institute) . [ECU-434] South, Stanley A. “Notes on the Treatment Methods for the Preservation of Iron and Wooden Objects.” (North Carolina Division of Archives and History) [n.d.]. [ECU-88] Spectre, P.H. “The Alvin Clark: The Challenge of the Challenge.” Woodenboat 52 (1983): 59–65. [ECU-265] Speier, R.F.G. “Ultrasonic Cleaning of Artifacts: A Preliminary Consideration.” American 26 (1961): 410–414. Spriggs, J. “The Recovery and Storage of Materials from Waterlogged Deposits at York.” The Conservator 4 (1980): 19–24. Stavrolakes, Niki. The Archaeology of Ships. New York: Henry Z. Walch, 1974. Stevens, Willis E. “The Excavation of a Mid-Sixteenth Century Basque Whaler in Red Bay, Labrador.” ICOM-WWWG Proceedings (Ottawa) (1981): 33–37. [ECU-90] Stewart, John, Lorne Murdock, and Peter Waddell. Reburial of the Red Bay Wreck as a Form of Preservation and Protection of the Historic Resource. Historic Resource Conservation Branch, Parks Canada, Ottawa, Ontario, Canada, KIA OM5. [ECU-524] Strang, Thomas J.K., and John E. Dawson. “Controlling Museum Fungal Problems.” CCI Technical Bulletin (No. 12, Canadian Conservation Institute, Ottawa) (1991). [ECU-371] Stoffyn-Eglit, Patricia and Dale E. Buckley. “The Micro-World of the Titanic.” Chemistry in Britain Vol. 31 No. 7, 1995. [ECU-658] Suenson-Taylor, Kirsten, Dean Sully, and Clive Orton. “Data in Conservation: the Missing Link in the Process.” Studies in Conservation Vol. 44 No. 3, 1999, pp. 184–194. [ECU-629] Switzer, R.R. “Some Technical Observations Concerning the Preservation of the Bertrand.” (National Park Service) (1969).

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Technology and Conservation Magazine. Technology and Conservation Magazine 4/93 and 2/94. Winter 1993 and Summer 1994. [ECU-520] Thomson, Gary. Museum Environment. London: Butterworths, 1986. Thorne, Robert M. “Site Stabilization Information Sources.” Technical Brief (National Park Service Cultural Resources, No. 12) (1991): 1–8. [ECU-374] Titford, Emma. “The Importance of Packing Objects.” British Maritime Museum Quarterly 2 (1989): 28–29. [ECU-92] —. “The Conservation of Artifacts from the New Old Spaniard.” British Maritime Museum Quarterly 2 (1989): 25–27. [ECU-91] Townsend, S. “The Conservation of Artifacts from Salt Water.” Diving Into the Past (Minnesota Historical Society: St. Paul) (1964). —. “Standard Conservation Procedures.” Underwater Archaeology, A Nascent Discipline (UNESCO, Paris) (1972): 251–256. Tuck, James A. “Wet Sites Archaeology at Red Bay, Labrador.” Wet Site Archaeology B.A. Purdy, ed., (1988): 103–111. Turner, W. “Appendix 3: Conservation of the Finds in Piercy, R., Mombasa Wreck Excavation: Second Preliminary Report, 1978.” International Journal of Nautical Archaeology 7 (1978): 317–319. Tylecote, R.F. “Durable Materials for Sea Water: The Archaeological Evidence.” International Journal of Nautical Archaeology 6 (1977): 269–283. [ECU-161] “Underwater Treasures Under the Microscope: Objects from the DeBrack Analyzed at Winterthur.” Winterthur Newsletter 34 [n.d.]: 14–15. Wachsman, Shelley, K. Raveh, and O. Cohen. “The Kenneret Boat Project, Part I. The Excavation and Conservation of the Kenneret Boat.” International Journal of Nautical Archaeology 16 (1987): 233–245. [ECU-129] Wainwright, Ian N.M. “The Science of Conservation : CCI’s New Variable—Pressure Scanning Electron Microscope with X-Ray.” CCI Newsletter (Canadian Conservation Institute) No. 29, 2002. [ECU-630] Walston, S. “Conservation in Australia.” Proceedings (ICCM National Conference, Canberra, Institute for the Conservation of Cultural Material, The Australian Museum, Sydney) (1976). Watkinson, David, ed. First Aid for Finds (United Kingdom Institute for Conservation, Rescue-The British Archaeological Trust, London) (1987). [ECU-429] Wedinger, Robert. “Preserving our Written Heritage.” Chemistry in Britain Vol. 28 No. 10, 1992. [ECU-659] Weier, L.E. “The Deterioration of Inorganic Material Under the Sea.” Bulletin (Institute of Archaeology, University of London II) (1973): 131–136. Werner, A.E.A. “Preservation Techniques.” Education in Chemistry 9 (1972): 131–133. —. “New Materials in the Conservation of Antiquities.” Museums Journal 64 (1972): 5–15. [ECU-404] “What is ‘Museum Quality’? A Curator Looks at Boat Restoration.” Woodenboat Vol. 144, 1998, pp. 84–90. [ECU-766] Winter, J. ed. “ICOM Reports on Technical Studies and Conservation.” Art and Archaeology Technical Abstracts 14, No. 2, [n.d.] [ECU-328] Wright, M.M. “ The Conservation Laboratories at Marischal Museum, Aberdeen.” Scottish Society for Conservation and Restoration Vol. 7 No. 2, 1996. [ECU-798] Young, Gregory. “Impact of Climatic Change on Conservation.” CCI Newsletter (Canadian Conservation Institute) No. 26, 2000. [ECU-631] Young, Janie Chester, “The State of the Art and the Artifact: A Regional Survey of Museum Collections,” Technology and Conservation Magazine. Vol. 11 Nos. 2–3 (Summer–Fall 1992): 10–16.

Figure 4.

Figure 5.

Chapter 2 Archaeological Wood

WOOD FORMATION AND DEGRADATION—THEORY Wood technology and tool making has surpassed virtually all other human worked materials in variety of use and multiplicity of properties. On many archaeological sites, wood, or wooden remains, make up most of the primary artifacts, hence its inclusion in this manual as the first material type. Wood is a durable easily worked organic material produced by trees and shrubs. Human tool manufacturing in wood likely pre-dates culture and language. It was used to make a multitude of diverse artifacts from weapons, homes, and shelters, to musical instruments, shoes, and ships. But in order to understand wood use in tools and artifacts it is necessary to understand some of wood’s characteristics as well as its make-up. Wood, like some modern materials such as plastic, has many different traits and each wood type had its historical use. For example, white oak is strong, durable, and reasonably waterproof but its too brittle make a good bow or handle for a digging tool and lacks the flexibility of yew or ash. Elm is renown for its mallet head endurance and yellow and white pines were easily worked and flexible but not exceedingly durable or strong. Other woods such as cedar are both strong and long lasting in a variety of uses. Pre-modern people were taught the value of each type of wood according to cultural need. Therefore, in all its variety of species, wood cannot truly be looked upon as a homogenous substance, but rather as a group of materials with varying properties used to produce a myriad of artifacts. A good deal of research has been conducted on archaeological wood. Some of the classic inquiries include H. J. Plenderleith and A.E.A. Werner’s, The Conservation of Antiquities and Works of Art, 1956, or A. J. Stamm’s earlier work on the search for a water soluble wax. Other articles include Brorson Christensen and J. de Jong’s prolonged search for methods to classify the degradation of archaeological wood. Another classic reference found in most museums is, B. Muhlenthaaler, Lars Barkman, and Noack’s Conservation of Waterlogged Wood and Wet Leather, 1973. Yet archaeologists and conservators are not the only people interested in archaeological wood. Until fairly recently wood anatomy and taxonomy have been the exclusive purview of biologists and wood scientists who have also produced good reference works such as A.J. Panshin and C. de Zeeuw’s, Textbook of Wood Technology, 1970, which is a very useful aid in the microscopic identification of wood species. 35

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Wood taxonomy breaks down all species into three categories, monocotyledons, hardwoods (dicotyledons and angiosperms), and softwoods (gymnosperms and coniferals). Most archaeological artifacts are made of hardwoods or softwoods, though monocotyledons such as palm and bamboo were used in the tropics. Hardwoods include birch, oak, elm, beech, cherry, hickory, maple, willow, walnut, and sweet gum to name a few, and all of these tree types come in more than one variety. Softwoods include the many varieties of pines, fir, spruce, hemlock, redwood, cedar, and larch. Generally speaking hardwoods are more dense and complex than softwoods. Looking at a log that has been crosscut or sectioned from the outside inward you first notice the protective bark on the outside. Just inside the bark is a thin layer, usually less than an inch in thickness called the cambrium or sapwood. This layer is the only living part of wood and is made up of phloem cells that conduct the food manufactured in the leaves to the remainder of the tree and the roots. Inside the cambrium is the heartwood made up of xylem cells that conduct water from the root to the upper extremities of the tree. The heartwood is what we are most concerned with as conservators as this is the structure of the tree that is most useful for manufacturing tools and artifacts. Radiating out from the heartwood are rays consisting of ray cells that help distribute water from the roots throughout the tree. Inside the wood tree cells are arranged longitudinally except for the ray cells. Since the phloem is the only living part of a tree trunk the wood is successively formed of phloem cells. Each year as these cells die they are surrounded by another year’s growth and move to the interior of the tree forming the heartwood. These wood cells, called tracheids, are bean pod shaped, closely bundled together, and gathered around vessels that permeate the wood. Wood cells are largely hollow. The cavity in the wood cell is known as a lumina. Early wood (spring growth) cells are larger and longer than late wood (late summer and fall) cells that tend to be smaller with thicker cell walls. Early wood appears light colored while late wood looks dark giving wood its distinctive annular rings. Softwood tracheids are up to 7mm long in early wood and 25–80 microns (1 millionth of a meter) in diameter shrinking to 5 microns by late season. Hardwood tracheids are smaller and denser at up to 1.5 mm in length and varying 1 to 10 microns in diameter depending on the season (Pearson, 1987; 57). Wood cells are made of complex carbohydrate molecules of cellulose, hemicellulose, lignin, and holocellulose. Cellulose is by far the most important of these molecules and makes up the greatest percentage of a wood cell. Cellulose molecules join together to form micro-fibrils that in turn, create macro-fibrils that give wood cell walls their strength and durability. Tracheid cell walls are permeable to an extent depending on the bordered pits. Pits are holes in the cell walls that allow water to pass through from one cell to the next, but only if the valve (margo and torus) in the pit is open. On dying early wood cell pits close off (aspirate) while late wood pits remain open (nonaspirated), leading to the contradiction that although late wood is denser than early wood, it is also more permeable.

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Figure 6. Wood is mainly comprised of the complex carbohydrate cellulose. Micro-fiber directions in the secondary cell wall (S1, S2, S3) are responsible for the overall drying behavior. Illustration by Nathan Richards.

Wood cells contain a primary cell wall and the secondary cell wall. Conservators are most concerned with the secondary tracheid wall as it is accountable for most of wood’s strength. However, the secondary cell wall is also subject to the greatest damage. The secondary cell wall is arranged in three distinct layers S1, S2, and S3. As can be seen in the illustration the fibril orientation of each of these layers is different as is the thickness of each layer. S2 dominates the secondary cell wall and the fibril direction spirals longitudinally around the core of the wood cell. The S1

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and S3 fibrils lay nearly perpendicular to the longitudinal direction the wood cell. The orientation of the fibrils is key to how wood expands and contracts with water absorption and desorption. Since S2 dominates, wood generally expands more in cross section than lengthwise when it absorbs water. Cell walls are subject to breakdown through physical weathering, the actions of micro-organisms, or chemical dissolution through acids, alkaloids, and pollutants. In fact, the structure and preservation of the largest of the secondary wood cell layers, S2, determines to a great extent how the wood in any given artifact has held up over time. The orientation of the secondary wood cell wall fibers also determines that damage to wood will manifest in shrinkage and collapse in three directions. Tangential and radial shrinkage will be greatest if the S2 layer is damaged and longitudinal shrinkage will manifest if S1 and S3 are greatly damaged. Collapse and shrinkage are technical terms used to describe how water interacts with archaeological wood. The water logging process permanently damages wood causing it to collapse and shrink when it dehydrates. The amount and direction of collapse and shrinkage are indicators of how badly damaged the wood is on a microscopic level and which layers have sustained the greatest impact from the waterlogging process (see section on waterlogging).

Figure 7. The three directions of collapse and shrinkage in Archaeological Wood. Illustration by Nathan Richards.

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ARCHAEOLOGICAL WOOD—THEORY Archaeological wood can be highly degraded or may be no different than the stout objects we use or come into contact with everyday. Wooden artifacts are obviously much older than the sort we deal with daily and may show their age in the form of structural weakness, cracking, discoloration, face checking, or a weathered appearance. In most instances archaeological wood has been attacked by living organisms on both a microscopic and macroscopic level, causing a weakening in its structure and possibly the destruction of its outer surface. Bacteria and fungi living in the ground will digest the complex carbohydrates that make up the wood and it will decay depending largely on the moisture content and drainage of the soil. Other creatures such as termites can quickly destroy and consume artifacts made of wood. Various chemical pollutants and acids can also break down wood lying in the soil while acidic metallic salts from corroding metal may break down wood at a cellular level and even mimic the shape of wood cells that it has replaced. Still other wooden artifacts interred below the water table, in lakes, rivers, or oceans, are likely to be waterlogged. Dry, waterlogged, wet, or even damp wood recovered from an archaeological site will need the attention of the Minimal Intervention Laboratory staff. It cannot be assumed by appearance alone that wood is stable and needs no further conservation treatment. The inclusion of metal fasteners, stains, and dirt likely mean that some form of conservation intervention must be considered.

WATERLOGGED WOOD THEORY Waterlogged wood can be defined as wood that contains little or no interstitial air in its cellular spaces, capillaries and micro-capillaries. It has also been altered (weakened) by the micro-degradation of the cell walls. Waterlogged wood demonstrates a moisture content (MC) at or above the fiber saturation point (FSP) or that point at which all wood fibers and micro-fibrils in the cell walls are saturated with water. On dehydration waterlogged wood can exhibit cellular collapse at or above the FSP as water rushes out of the wood cells one at a time. The sudden rush of water from the interior of the cell is not easily described and best seen through a microscope. Since water exhibits a high cohesiveness (capillary tension) it pulls the wood cell walls inward as it rushes out of a cell collapsing the wood cell in a microscopic, yet violent act. Collapse is easily observable with the naked eye in waterlogged archaeological wood that is allowed to dry, as fissures and cracks appear suddenly in the structure of the wood. Even wet or damp waterlogged wood will collapse if it is allowed to rest in the atmosphere without constant dousing with water. Capillary tension collapse is a permanent condition in dehydrated waterlogged wood. Wood cells, even on rehydration will not expand to their previous size. Further dehydration below the fibre saturation point will lead to Shrinkage of the cell walls and further distortion of dried waterlogged wood. Shrinkage, unlike

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collapse, is to some extent reversible on re-hydration. It can be defined as the loss of water in the cell wall through evaporation. This water is normally locked into the cellulosic fibrils but can evaporate in dry conditions. Green wood or unseasoned wood, even with a considerable water content, contain air pockets within the tracheids. These air pockets expand on dehydration allowing water to leave green wood cells without causing the tremendous capillary tension pressure responsible for the collapse of waterlogged wood. Green wood does exhibit some reversible shrinkage of the cell walls on complete or near dehydration and both green and waterlogged wood swell 8% to 12% when fully saturated depending on specie.

IMPREGNATION AND BULKING—THEORY Capillary tension collapse and shrinkage complicate the process of treating waterlogged wooden artifacts. It is easy to see in the flow chart on page 60 that the procedure for treating waterlogged wood is far more complex than that used to treat dry recovered archaeological wood. Conservators treating waterlogged wood attempt to arrest or mitigate collapse and shrinkage and add strength to the artifact, to maintain its dimensions and appearance. There are essentially two methods for conserving waterlogged wood, impregnation and bulking. Impregnation is defined as the filling of all wood spaces and wood cells with an inert material that hardens upon drying in order to add strength to the wood and at the same time reduce capillary tension collapse. Collapse is reduced when the impregnating agent demonstrates less surface cohesion than water. Impregnation is reserved for waterlogged wood that is in very bad condition, where much of the cellulose in the cell walls has been destroyed and removed. Impregnating agents include polyethylene glycol (PEG) of molecular weight greater than 1000, alum, rosin, barium borate, and monomers that can be polymerized within the wood. Bulking is a less drastic procedure than impregnation. It can be defined as the insertion of an inert material into the cell walls to replace missing cellulose in order to strengthen the wood cell walls and make them more resistant to collapse and shrinkage. As with impregnating agents, bulking agents reduce collapse by lessening water’s surface cohesion. Bulking is used on waterlogged wood that has little to moderate microscopic damage and still retains much of its cellulose. Bulking agents include PEG with molecular weight less than 1000, various sugars, salts, or vinyl monomers. Bulking and impregnation are proven and highly successful treatments in the conservation of waterlogged wood, the difficulty for the conservator lies in choosing which treatment to perform. In some instances the choice is easy, highly degraded wood is impregnated and very lightly degraded wood is bulked. Fortunately there are objective tests and analysis available to help make this decision. Wood analysis is a continuing theme is waterlogged wood conservation research. Pioneers such as Lars Barkman, Moren and Centerwall, R. M. Organ

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and A. J. Stamm all agreed that the problem with waterlogged wood is that it is not uniform, but rather a combination of sound and degraded wood. Although these researchers agreed that analysis should determine the type of treatment, laboratory tests were not standardized. Experimental tests followed objective or subjective paradigms but for many years did nothing to solve the problem presented by waterlogged wood. Finally however, in the 1970s, J. de Jong, assigned moisture content (MC) to B. Christensen’s three subjective waterlogged wood classifications, and for the first time produced a simple and useful way to analyze waterlogged wood. Christensen Classification A. Very Soft—Little Cellulose B. Thin Zone—Little Cellulose, Consistency of Old Rope C. Little Deterioration—Non-permeable

deJong Classification I. >400% MC II. 185%–400% MC III.

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